稀土掺杂NaYF_4上转换发光纳米晶的水相合成、表征及其生物应用探索
|
摘要
近年来,随着纳米科学与技术的发展,稀土掺杂的荧光纳米粒子以其独特的发光特性在光学、电子学、信息学和生物学等领域表现出潜在的应用价值。自上个世纪50年代人们发现上转换这一现象以来,上转换发光材料研究一直是材料科学领域的研究热点之一。稀土掺杂的上转换发光纳米材料在生物标记、荧光在体成像、激光和光纤通信等领域有着广泛的应用。上转换发光材料与其他荧光材料相比,具有发射谱线窄,发光性质稳定,无光漂白现象,荧光信噪比高等优点,因此在生物医学领域有重要的潜在应用价值。最近,研究人员已经将上转换发光材料成功应用于细胞成像、免疫分析和DNA检测等。为了实现其在生物医学领域的广泛应用,人们希望制备出发光效率更高,尺寸更小,分散性更好的上转换发光材料。本论文主要围绕稀土掺杂的上转换发光纳米晶的合成与生物应用展开一系列研究工作,并得到了一些创新性结果,主要内容如下:
1.采用柠檬酸钠作为螯合剂结合水热反应过程合成出不同尺寸与形貌的立方与六角结构的NaYF_4:Yb~(3+), Er~(3+)纳米晶。对Fˉ离子的量、柠檬酸的量、水热反应温度和水热时间等参数对纳米晶的形貌、尺寸、结构以及上转换发光性质的影响进行了分析,并对NaYF_4:Yb~(3+), Er~(3+)纳米晶的上转换发光性质进行了研究。研究发现,过量的Fˉ离子能够有效地降低样品的结晶温度,在相对较低的水热温度下,就能获得结晶性较好的纳米晶;通过调节柠檬酸钠的量能够有效控制样品的尺寸、形貌和晶格结构,柠檬酸分子与稀土阳离子强的螯合能力能有效地控制NaYF_4:Yb~(3+), Er~(3+)纳米晶的生长速度,相变时间,其与六角相NaYF_4晶核的{0001}晶面的选择性吸附作用,使晶体在生长过程中,在六个对称的方向:±[101_0],±[011_0]和±[11_00]的生长速率相对较快,最终形成了六角形的NaYF_4亚微米片。在980 nm激光激发下,观察到了立方相纳米粒子和六角相亚微米片的上转换发光,其绿光与红光上转换发光过程均属于双光子发光过程。相对与绿光发射,样品的红光上转换发射相对较强。实验证明,样品表面的柠檬酸分子上的高能有机振动基团引起的多声子驰豫过程和Er~(3+)离子之间的交叉驰豫相互作用是样品红色上转换发射较强的主要原因。
2.以聚乙烯亚胺(PEI)作为表面活性剂,采用水热合成法,首次合成出了多孔结构的六角相NaYF_4:Yb~(3+), Er~(3+)空心纳米球。氮气吸附/脱附曲线证明了样品的多孔特性。通过对PEI浓度、水热反应温度和水热反应时间等参数对样品的形貌、尺寸和结构等的影响,讨论了六角相NaYF_4:Yb~(3+), Er~(3+)空心纳米球的生长机理和上转换发光性质。实验结果发现,适当的PEI浓度和水热反应条件是六角相NaYF_4:Yb~(3+), Er~(3+)空心纳米球形成的关键因素。对不同水热时间制备的样品进行表征分析发现,样品经历了从立方相NaYF_4:Yb~(3+), Er~(3+)纳米晶到六角相NaYF_4:Yb~(3+), Er~(3+)自组装纳米线,再到六角相NaYF_4:Yb~(3+), Er~(3+)空心纳米球的相变和形貌演变过程,PEI诱导的Ostwald熟化过程是样品形成的主要机理。在980 nm光激发下,粒子显示出较强的上转换发光。由于掺杂离子浓度较高,相邻的Er~(3+)离子之间有较强的交叉驰豫,加上样品表面高能的有机振动基团引起的多声子驰豫过程的影响,样品显示出红色上转换发射相对较强的特点。
3.以不同分子量的PEI聚合物为表面活性剂,水/醇溶液为溶剂,利用水热/热溶剂法合成出尺寸可控的水溶性的NaYF_4:Yb~(3+), Er~(3+)纳米粒子。实验发现,在相同的水热条件下,用高分子量的聚合物(HPEI)合成的样品比用低分子量的聚合物(LPEI)合成的样品的尺寸要小。值得注意的是,在相同功率的980 nm激光激发下,小尺寸的样品的上转换发光比同条件下大尺寸的样品的上转换发光强。结合晶体生长理论,我们认为,结晶性的差别是样品上转换发光强度不同的原因,高分子量的聚合物能够降低粒子的生长速率,有利于小尺寸、结晶性好的粒子生成。细胞毒性实验和荧光免疫分析实验证明所制备的样品具有很好的生物相容性。
In the recent years, with the development of nanoscience and nanotechnology, fluorescent nanocrystals have attracted much attention due to their unique optical properties. There has been considerable research on upconverting phosphors since initial interest in the late 1950s. Rare-earth-doped upconverting materials have wide potential applications in many fields, including phosphors, display monitor, lasers and amplify for fiber-optic communications. Compared with other fluorescent materials, such as organic dye, the upconverting materials have several advantages in optical properties of narrow band emissions, high photostability, low background light, nonfading, and no significant influence of environment under near infrared radiation, so they can be used as biological labels materials. Rare-earth-doped upconverting nanocrystals have been reported to be used for the cell imaging, detection of nucleic acid and immunoassay. The nanocrystals should be highly efficient emission, size-controlled and monodisperse for biological applications. So developing synthetic technologies and researching the quenching mechanisms of luminescence are very important to both fundamental research and practical application. Surrounding the rare-earth doped fluoride nanocrystals, this dissertation presents a systematic research about preparation, characterization and biomedical application of nanoparticles. Now, some original results are obtained from our experiments, the main results are outlined as followings:
1. Develop a simple hydrothermal method for synthesis of different sizes and morphology of cubic and hexagonal structure of NaYF_4: Yb~(3+), Er~(3+) nanocrystals using sodium citrate as a chelating agent. The effects of the amount of Fˉions and citrate as well as the hydrothermal temperature and hydrothermal time on the nano-crystalline morphology, size, structure, and up-conversion luminescence properties were analyzed in detail. The upconversion luminescence properties of the NaYF_4: Yb~(3+), Er~(3+) nanocrystals were also studied. It is found that excessive levels of Fˉion can effectively reduce the crystallization temperature of the sample, at a relatively low hydrothermal temperature, you can get nanocrystals with better crystallization; the size, morphology and crystal structure of the samples can be effectively controlled by adjusting the amount of sodium citrate; the strong chelating ability between rare earth cation and citric acid molecules can be able to effectively control the growth rate, phase-change time of NaYF_4: Yb~(3+), Er~(3+) nanocrystals; due to the selective coordination role of citrate with the {0001} crystal plane of the hexagonal NaYF_4 nuclei, during the crystal growth process, the growth rate of crystal relatively fast in the six symmetric directions:±[101_0],±[011_0] and±[11_00] and the hexagonal NaYF_4 sub-micron plates eventually formed. In the 980 nm laser excitation, the upconversion luminescence of cubic phase nanoparticles and hexagonal sub-micron plates is observed and its green and red upconversion luminescence process belongs to the two-photon process. Relative to green emission, the red up-conversion emission of samples is relatively strong. Experiments show that the multi-phonon relaxation induced by the high energy vibration groups of the citrate adsorbed on the sample surface and the cross-relaxation interaction between Er~(3+) ions in the samples are the main reasons for a strong red up-conversion emission.
2. The hexagonal-phase NaYF_4:Yb~(3+), Er~(3+) hollow nanospheres have been successfully prepared for the first time via a hydrothermal route with the aid of polyethylenimine (PEI) as a surfactant. The nitrogen adsorption/desorption isotherms demonstrated the porous nature of the NaYF_4 hollow nanospheres. Through discussing the effects of the PEI concentration, hydrothermal temperature and hydrothermal time on the morphology, size and structure of samples, the growth mechanism of hollow nanospheres was proposed. It was found that the appropriate PEI concentration and hydrothermal reaction conditions are the key factors to form hexagonal NaYF_4: Yb~(3+), Er~(3+) hollow nanospheres. By analysing the character of the samples prepared in different hydrothermal time, it was revealed that the samples suffered morphology evolution and the phase transition from the cubic phase NaYF_4: Yb~(3+), Er~(3+) nanocrystals to the hexagonal phase NaYF_4: Yb~(3+), Er~(3+) self-assembled nanowires, to the hexagonal phase NaYF_4: Yb~(3+), Er~(3+) hollow nanospheres; PEI-induced Ostwald ripening process is the main mechanism of the formation of the sample. In the 980 nm light excitation, the particles showed strong up-conversion luminescence emission. As the strong cross-relaxation process exist among neighboring Er~(3+) ions due to the relatively higher doping concentration and the multi-phonon relaxation induced by the organic high-energy vibration of the sample surface, the samples showed relatively strong red upconversion emission.
3. The effect of branched polyethylenimine with different chain lengths, used as the surfactants in the preparation of water-soluble NaYF_4:Yb~(3+), Er~(3+) nanocrystals following solvothermal approach, on the infrared (IR) to visible photon upconversion has been studied. It was found that under the same hydrothermal conditions, the size of the sample synthesized with high molecular weight polymer (HPEI) is smaller than those with low molecular weight polymer (LPEI). Interestingly, in the same power 980 nm laser excitation, the upconversion luminescence intensity of the sample with small size is stronger than that of the samples with large size. Combining the crystal growth theory, we believe that the difference in the sample crystallinity is the main reason for the different up-conversion luminescence intensity. High molecular weight polymer can reduce the particle growth rate and favor the formation of nanoparticles with small size and good crystallinity. Cytotoxicity test and fluorescent immunoassay results show the obtained nanoparticles have good biocompatibility.
1.采用柠檬酸钠作为螯合剂结合水热反应过程合成出不同尺寸与形貌的立方与六角结构的NaYF_4:Yb~(3+), Er~(3+)纳米晶。对Fˉ离子的量、柠檬酸的量、水热反应温度和水热时间等参数对纳米晶的形貌、尺寸、结构以及上转换发光性质的影响进行了分析,并对NaYF_4:Yb~(3+), Er~(3+)纳米晶的上转换发光性质进行了研究。研究发现,过量的Fˉ离子能够有效地降低样品的结晶温度,在相对较低的水热温度下,就能获得结晶性较好的纳米晶;通过调节柠檬酸钠的量能够有效控制样品的尺寸、形貌和晶格结构,柠檬酸分子与稀土阳离子强的螯合能力能有效地控制NaYF_4:Yb~(3+), Er~(3+)纳米晶的生长速度,相变时间,其与六角相NaYF_4晶核的{0001}晶面的选择性吸附作用,使晶体在生长过程中,在六个对称的方向:±[101_0],±[011_0]和±[11_00]的生长速率相对较快,最终形成了六角形的NaYF_4亚微米片。在980 nm激光激发下,观察到了立方相纳米粒子和六角相亚微米片的上转换发光,其绿光与红光上转换发光过程均属于双光子发光过程。相对与绿光发射,样品的红光上转换发射相对较强。实验证明,样品表面的柠檬酸分子上的高能有机振动基团引起的多声子驰豫过程和Er~(3+)离子之间的交叉驰豫相互作用是样品红色上转换发射较强的主要原因。
2.以聚乙烯亚胺(PEI)作为表面活性剂,采用水热合成法,首次合成出了多孔结构的六角相NaYF_4:Yb~(3+), Er~(3+)空心纳米球。氮气吸附/脱附曲线证明了样品的多孔特性。通过对PEI浓度、水热反应温度和水热反应时间等参数对样品的形貌、尺寸和结构等的影响,讨论了六角相NaYF_4:Yb~(3+), Er~(3+)空心纳米球的生长机理和上转换发光性质。实验结果发现,适当的PEI浓度和水热反应条件是六角相NaYF_4:Yb~(3+), Er~(3+)空心纳米球形成的关键因素。对不同水热时间制备的样品进行表征分析发现,样品经历了从立方相NaYF_4:Yb~(3+), Er~(3+)纳米晶到六角相NaYF_4:Yb~(3+), Er~(3+)自组装纳米线,再到六角相NaYF_4:Yb~(3+), Er~(3+)空心纳米球的相变和形貌演变过程,PEI诱导的Ostwald熟化过程是样品形成的主要机理。在980 nm光激发下,粒子显示出较强的上转换发光。由于掺杂离子浓度较高,相邻的Er~(3+)离子之间有较强的交叉驰豫,加上样品表面高能的有机振动基团引起的多声子驰豫过程的影响,样品显示出红色上转换发射相对较强的特点。
3.以不同分子量的PEI聚合物为表面活性剂,水/醇溶液为溶剂,利用水热/热溶剂法合成出尺寸可控的水溶性的NaYF_4:Yb~(3+), Er~(3+)纳米粒子。实验发现,在相同的水热条件下,用高分子量的聚合物(HPEI)合成的样品比用低分子量的聚合物(LPEI)合成的样品的尺寸要小。值得注意的是,在相同功率的980 nm激光激发下,小尺寸的样品的上转换发光比同条件下大尺寸的样品的上转换发光强。结合晶体生长理论,我们认为,结晶性的差别是样品上转换发光强度不同的原因,高分子量的聚合物能够降低粒子的生长速率,有利于小尺寸、结晶性好的粒子生成。细胞毒性实验和荧光免疫分析实验证明所制备的样品具有很好的生物相容性。
In the recent years, with the development of nanoscience and nanotechnology, fluorescent nanocrystals have attracted much attention due to their unique optical properties. There has been considerable research on upconverting phosphors since initial interest in the late 1950s. Rare-earth-doped upconverting materials have wide potential applications in many fields, including phosphors, display monitor, lasers and amplify for fiber-optic communications. Compared with other fluorescent materials, such as organic dye, the upconverting materials have several advantages in optical properties of narrow band emissions, high photostability, low background light, nonfading, and no significant influence of environment under near infrared radiation, so they can be used as biological labels materials. Rare-earth-doped upconverting nanocrystals have been reported to be used for the cell imaging, detection of nucleic acid and immunoassay. The nanocrystals should be highly efficient emission, size-controlled and monodisperse for biological applications. So developing synthetic technologies and researching the quenching mechanisms of luminescence are very important to both fundamental research and practical application. Surrounding the rare-earth doped fluoride nanocrystals, this dissertation presents a systematic research about preparation, characterization and biomedical application of nanoparticles. Now, some original results are obtained from our experiments, the main results are outlined as followings:
1. Develop a simple hydrothermal method for synthesis of different sizes and morphology of cubic and hexagonal structure of NaYF_4: Yb~(3+), Er~(3+) nanocrystals using sodium citrate as a chelating agent. The effects of the amount of Fˉions and citrate as well as the hydrothermal temperature and hydrothermal time on the nano-crystalline morphology, size, structure, and up-conversion luminescence properties were analyzed in detail. The upconversion luminescence properties of the NaYF_4: Yb~(3+), Er~(3+) nanocrystals were also studied. It is found that excessive levels of Fˉion can effectively reduce the crystallization temperature of the sample, at a relatively low hydrothermal temperature, you can get nanocrystals with better crystallization; the size, morphology and crystal structure of the samples can be effectively controlled by adjusting the amount of sodium citrate; the strong chelating ability between rare earth cation and citric acid molecules can be able to effectively control the growth rate, phase-change time of NaYF_4: Yb~(3+), Er~(3+) nanocrystals; due to the selective coordination role of citrate with the {0001} crystal plane of the hexagonal NaYF_4 nuclei, during the crystal growth process, the growth rate of crystal relatively fast in the six symmetric directions:±[101_0],±[011_0] and±[11_00] and the hexagonal NaYF_4 sub-micron plates eventually formed. In the 980 nm laser excitation, the upconversion luminescence of cubic phase nanoparticles and hexagonal sub-micron plates is observed and its green and red upconversion luminescence process belongs to the two-photon process. Relative to green emission, the red up-conversion emission of samples is relatively strong. Experiments show that the multi-phonon relaxation induced by the high energy vibration groups of the citrate adsorbed on the sample surface and the cross-relaxation interaction between Er~(3+) ions in the samples are the main reasons for a strong red up-conversion emission.
2. The hexagonal-phase NaYF_4:Yb~(3+), Er~(3+) hollow nanospheres have been successfully prepared for the first time via a hydrothermal route with the aid of polyethylenimine (PEI) as a surfactant. The nitrogen adsorption/desorption isotherms demonstrated the porous nature of the NaYF_4 hollow nanospheres. Through discussing the effects of the PEI concentration, hydrothermal temperature and hydrothermal time on the morphology, size and structure of samples, the growth mechanism of hollow nanospheres was proposed. It was found that the appropriate PEI concentration and hydrothermal reaction conditions are the key factors to form hexagonal NaYF_4: Yb~(3+), Er~(3+) hollow nanospheres. By analysing the character of the samples prepared in different hydrothermal time, it was revealed that the samples suffered morphology evolution and the phase transition from the cubic phase NaYF_4: Yb~(3+), Er~(3+) nanocrystals to the hexagonal phase NaYF_4: Yb~(3+), Er~(3+) self-assembled nanowires, to the hexagonal phase NaYF_4: Yb~(3+), Er~(3+) hollow nanospheres; PEI-induced Ostwald ripening process is the main mechanism of the formation of the sample. In the 980 nm light excitation, the particles showed strong up-conversion luminescence emission. As the strong cross-relaxation process exist among neighboring Er~(3+) ions due to the relatively higher doping concentration and the multi-phonon relaxation induced by the organic high-energy vibration of the sample surface, the samples showed relatively strong red upconversion emission.
3. The effect of branched polyethylenimine with different chain lengths, used as the surfactants in the preparation of water-soluble NaYF_4:Yb~(3+), Er~(3+) nanocrystals following solvothermal approach, on the infrared (IR) to visible photon upconversion has been studied. It was found that under the same hydrothermal conditions, the size of the sample synthesized with high molecular weight polymer (HPEI) is smaller than those with low molecular weight polymer (LPEI). Interestingly, in the same power 980 nm laser excitation, the upconversion luminescence intensity of the sample with small size is stronger than that of the samples with large size. Combining the crystal growth theory, we believe that the difference in the sample crystallinity is the main reason for the different up-conversion luminescence intensity. High molecular weight polymer can reduce the particle growth rate and favor the formation of nanoparticles with small size and good crystallinity. Cytotoxicity test and fluorescent immunoassay results show the obtained nanoparticles have good biocompatibility.
引文
[1]白春礼.纳米科技及其发展前沿[J],微纳电子技术, 2002,1:2-5.
[2]张志焜,崔作林.纳米技术与纳米材料[M],北京:国防工业出版社,2000.
[3]顾宁,付德刚,张海黔.纳米技术及应用[M],北京:人民邮电出版社,2002.
[4]杨志伊.纳米科技[M],北京:机械工业出版社,2004.
[5]薛增泉.纳米电子学[J],现代科学仪器,1998,1-2:8-12.
[6]薛群基,徐康.纳米化学[J],化学进展,2000,12(4):431-444.
[7]温诗铸.纳米摩擦学[J],北京:清华大学出版社,1998.
[8]陈慧文,容敏智,章明秋.分子与纳米自组装材料的研究进展[J],材料导报,2002:16(8):59-61.
[9] Feynman R P. There is plenty of room at the bottom, Lecture at the annual meeting of the American Physical Society at the California Institute of Technology[R]. 1959.
[10]周瑞发,韩雅芳,陈祥宝.纳米材料技术[M],北京:国防工业出版社,2003.
[11] Yu S H, Bio-inspired Crystal Growth by Synthetic Templates [J]. Top Curr Chem, 2007, 271: 79-118.
[12] Cushing B L, Kolesnichenko V L, O’Connor C J. Recent Advances in the Liquid-Phase Syntheses of Inorganic Nanoparticles [J]. Chem. Rev, 2004, 104: 3893-3946
[13] Smigelskas A D, Kirkendall E O. Zinc Diffusion in Alpha Brass [J]. Trans. AIME, 1947, 171: 130-142.
[14]全国第一届溶胶-凝胶会议论文集“特种玻璃”[C],1990, 7: 3.
[15] Wong E M, Bonevich J E, Searson P C. The growth kinetics of nanocrystalline ZnO particles from colloidal suspensions [J]. J Phys Chem B, 1998, 102: 7770-7775.
[16] Lakshmi B B, Dorhout P K, Martin C R. Sol-gel template synthesis of semiconductor nanostructures [J]. Chem Mater, 1997, 9: 857-862.
[17] Gu F, Wang S F, Lu M K, et al. Photoluminescence properties of SnO_2 nanoparticles synthesized by sol-gel method [J]. J Phys Chem B, 2004, 108: 8119-8123.
[18] You H P, Nogami M. Optical Properties and Local Structure of Eu~(3+) Ions in Sol?Gel TiO_2?SiO_2 Glasses [J]. J Phys Chem B, 2004, 108: 12003-12008.
[19] Ptatschek V, Schreder B, Herz K, et al. Sol-Gel Synthesis and Spectroscopic Properties of Thick Nanocrystalline CdSe Films [J]. J Phys Chem B, 1997, 101: 8898-8906.
[20] Gacoin T, Huignard A, Counio G, et al. Chemical Design of Nanostructured Luminescent Materials [J]. Mater Res Soc Symp Pro, 2000, 62.
[21]林君,苏锵,溶胶-凝胶法及其在稀土发光材料合成中的应用[J].稀土学报,1994, 1(15): 42-46.
[22]石士考,霍庆.无机粉末发光材料合成的新方法[J].无机盐工业,1999,31:20-22.
[23]王惠琴.4SrO·7A12O3: Eu发光材料的快速合成及X-射线衍射分析[J].发光学报, 1996,17 (增刊):72-73.
[24] Hoar T P, Schulman J H. Transparent Water-in-Oil Dispersions: the Oleopathic Hydro-Micelle [J]. Nature, 1943, 152:102-103.
[25] Schulman J H, Stoeckenius W, Prince L M. Mechanism of Formation and Structure of Microemulsions by Electron Microscopy [J]. J Phys Chem, 1959, 63(10), 1677-1680.
[26] Stevens M J, Robbins M O. Density Functional Theory of Ionic Screening: When Do Like Charges Attract? [J]. Europhys Lett, 1990, 12(1): 81-86.
[27] Mitchell D J, Ninham B W. Micelles, vesicles and microemulsions [J]. J Chem Soc Faraday Trans, 1981, 77: 601-629.
[28] Attard P, Mitchell D J, Ninham B W. Beyond Poisson-Boltzmann: Images and correlations in the electric double layer. I. Counterions only [J]. J Chem Phys, 1988, 88(8): 4987-4996.
[29]刘应亮,石春山.Eu~(3+)在xMF2-yYF3体系中光谱性质及其变化规律[J].发光学报,1990,11:22-28.
[30] Mai H X, Zhang Y W, Si R, et al. High-Quality Sodium Rare-Earth Fluoride Nanocrystals: Controlled Synthesis and Optical Properties [J]. J Am Chem Soc, 2006, 128: 6426-6436.
[31] Yi G S, Chow G M. Synthesis of Hexagonal-Phase NaYF_4: Yb, Er and NaYF_4:Yb, Tm Nanocrystals with Efficient Up-Conversion Fluorescence[J]. Adv Funct Mater, 2006, 16: 2324-2329.
[32] (a) Jun Y W, Lee J H, Choi J S, et al. Symmetry-Controlled Colloidal Nanocrystals: Nonhydrolytic Chemical Synthesis and Shape Determining Parameters[J]. J. Phys. Chem. B, 2005, 109: 14795-14806; (b) Burda C, Chen X B, Narayanan R, et al. Chemistry and properties of nanocrystals of different shapes [J]. Chem Rev, 2005, 105(4): 1025-1102.
[33]仲维卓,华素坤.晶体生长形态学[M].科学出版社.1999.
[34] Hong B H, Bae S C, Lee C W, et al. Ultrathin single-crystalline silver nanowire arrays formed in an ambient solution phase [J]. Science, 2001, 294(5541): 348-351.
[35] Puntes V F, Krishnan K M, Alivisatos A P. Colloidal nanocrystal shape and size control: The case of cobalt [J]. Science, 2001, 291(5511): 2115-2117.
[36] Peng X G. Mechanisms for the shape-control and shape-evolution of colloidal semiconductor nanocrystals [J]. Adv Mater, 2003, 15(5): 459-463.
[37]孙家跃,杜海燕.无机材料制造与应用[M].北京:化学工业出版社,2001.
[38] (a) Auzel F. Acad Sci (Paris) [Z]. 1966, 262:1016-1019. (b) Auzel F, Acad Sci(Paris) [Z]. 1966, 263: 819-821.
[39] Stephens R R, McFarlane R A. Diode-pumped upconversion laser with 100-mW output power [J]. Opt Lett, 1993, 18 (1): 34-36.
[40] Auzel F. Upconversion and Anti-Stokes Processes with f and d Ions in Solids [J]. Chem Rev, 2004, 104 (1): 139-174.
[41]张思远,毕宪章.稀土光谱理论[M].吉林科学技术出版社,1991.
[42]张立德,牟季美.开拓原子和物质的中间领域—纳米微粒与纳米固体[J].物理学报,1992,21,167-173.
[43] Stephens R R, Mc Farlane R A. Diode-pumped upconversion laser with 100-mW output power [J]. Opt Lett, 1993, 18(1): 34-36.
[44] Mo C, Yuan Z, Zhang L, et al. Infrared absorption spectra of nano-alumina [J]. Nanostructured Materials, 1993, 2(1): 47-54.
[45]蔡树芝,牟季美,张立德等.物理学报[J],1992,41:1620.
[46] Tabagi H, Ogawa H, Yamazaki Y, et al. Quantum size effects on photoluminescence in ultratfne Si particles [J]. Appl Phys Lett, 1990, 56: 2379-2380.
[47] Brus L. Squeezing light from silicon [J]. Nature, 1991, 353: 301-302.
[48] Heine F, Heumann E, Danger T, et al. Green upconversion continuous wave Er~(3+): LiYF_4 laser at room temperature [J]. Appl Phys Lett, 1994, 65(4): 383-384.
[49] Tanabe S, Hayashi H, Hanada T, et al. Fluorescence properties of Er~(3+) ions in glass ceramics containing LaF3 nanocrystals [J]. Optical Materials, 2002, 19(3): 343-349.
[50] Hampl J, Hall M, Mufti N A, et al. Up-converting phosphor reporters in immunochromatographic assays [J]. Analytical Biochemistry, 2001, 288: 176-187.
[51] Niedbala R S, Feindt H, Kardos K, et al. Detection of analytes by immunoassay using up-converting phosphor technology [J]. Analytical Biochemistry, 2001, 293: 22-30.
[52] Zijlmans H J M A A, Bonnet J, Burton J, et al. Detection of cell and tissue surface antigens using upconverting phosopors: a new reports technology [J]. Anal Biochem, 1999, 267: 30-36.
[53] Lim S F, Riehn R, Ryu W S, et al. In Vivo and Scanning Electron Microscopy Imaging of Upconverting Nanophosphors in Caenorhabditis elegans [J]. Nano Lett, 2006, 6(2):169-174.
[54] Corstjens P, Zuiderwijk M, Brink A, et al. Use of upconverting phosphor reporters in lateral-flow assays to detect specific nucleic acid sequences: a rapid, sensitive DNA test to identify human papillomavirus type 16 infection [J]. Clinical Chem, 2001, 47: 1885-1893.
[55] van de Rijke F, Zijlmans H, Li S, et al. Upconverting phosphor reports for nucleic acid microarrays [J]. Nature Biotech, 2001, 19: 273-276.
[56] Zhang P, Steelant W, Kumar M, et al. Versatile Photosensitizers for hotodynamic Therapy at Infrared Excitation [J]. J Am Chem Soc, 2007, 129: 4526-4527.
[57] Kr?mer K W, Biner D, Frei G, et al. Hexagonal Sodium Yttrium Fluoride Based Green and Blue Emitting Upconversion Phosphors [J]. Chem Mater, 2004, 16(7): 1244-1251.
[58] Menyuk N, Dwight K, Pierce J W. NaYF_4: Yb, Er– an efficient upconversion phosphor [J]. Appl Phys Lett, 1972, 21(4): 159-161.
[59] Suyver J F, Grimm J, van Veen M K, et al. Upconversion spectroscopy and properties of NaYF_4 doped with Er~(3+), Tm~(3+) and/or Yb~(3+) [J]. J Lumin, 2006, 117: 1-12.
[60] Yi G S, Chow G M. Synthesis of Hexagonal-Phase NaYF_4:Yb,Er and NaYF_4:Yb,Tm Nanocrystals with Efficient Up-Conversion Fluorescence [J]. Adv Funct Mater, 2006, 16: 2324-2329.
[61] Heer S, K?mpe K, Güdel H U, et al. Highly Efficient Multicolour Upconversion Emission in Transpatent Colloids of Lanthanide-Doped NaYF_4 Nanocrystals [J]. Adv Mater, 2004, 16: 2102-2105.
[62] Zeng J H, Su J, Li Z H, et al. Synthesis and Upconversion Luminescence of Hexagonal-Phase NaYF_4:Yb,Er Phosphors of Controlled Size and Morphology [J]. Adv Mater, 2005, 17, 2119-2123.
[63] Yi G S, Lu H C, Zhao S Y, et al. Synthesis, Characterization, and Biological Application of Size-Controlled Nanocrystalline NaYF_4: Yb, Er Infrared-to-Visible Up-Conversion Phosphors [J]. Nano Lett, 2004, 4(11): 2191-2196.
[64] Sch?fer H, Ptacek P, K?mpe K, et al. Lanthanide-Doped NaYF_4 Nanocrystals in Aqueous Solution Displaying Strong Up-Conversion Emission [J]. Chem Mater, 2007, 19(6): 1396-1400.
[65] Wang L Y, Li Y D. Controlled Synthesis and Luminescence of Lanthanide Doped NaYF_4 Nanocrystals [J]. Chem Mater, 2007, 19(4): 727-734.
[66] Wang L Y, Li Y D. Green upconversion nanocrystals for DNA detection [J]. Chem Commun, 2006, 24: 2557-2559.
[67] Chan W C W, Nie S M. Quantum dot bioconjugates for ultrasensitive nonisotopic detection [J]. Science, 1998, 281(5385) : 2016-2018.
[68] Chatterjee D K, Rufaihah A J, Zhang Y. Upconversion fluorescence imaging of cells and small animals using lanthanide doped nanocrystals [J]. Biomaterials 2008, 29: 937-943.
[69] Feijo J A, Moreno N. Imaging plant cells by two-photon excitation [J]. Protoplasma, 2004, 223(1): 1-32.
[70] Patra A, Friend C S, Kapoor R, et al. Upconversion in Er~(3+): ZrO_2 Nanocrystals [J]. J Phys Chem B 2002, 106(8): 1909-1912.
[71] Patra A, Friend C S, Kapoor R, et al. Fluorescence Upconversion Properties of Er~(3+)-Doped TiO_2 and BaTiO3 Nanocrystallites [J]. Chem Mater, 2003, 15(19): 3650-3655.
[72] Vetrone F, Boyer J C, Capobianco J A, et al. Effect of Yb~(3+) Codoping on the Upconversion Emission in Nanocrystalline Y2O3:Er~(3+) [J]. J Phys Chem B 2003, 107(5): 1107-1112.
[73] Stouwdam J W, van Veggel F C J M. Near-infrared Emission of Redispersible Er~(3+), Nd~(3+), and Ho~(3+) Doped LaF3 Nanoparticles [J]. Nano Lett, 2002, 2(7), 733-737.
[74] Vetrone F, Christopher Boyer J, Capobianco J A, et al. Concentration-Dependent Near-Infrared to Visible Upconversion in Nanocrystalline and Bulk Y2O3:Er~(3+) [J]. Chem Mater, 2003, 15(14): 2737-2743.
[75] Vetrone F, Christopher Boyer J, Capobianco J A. NIR to Visible Upconversion in Nanocrystalline and Bulk Lu2O3:Er~(3+) [J]. J Phys Chem B 2002, 106(22): 5622-5628.
[76] Capobianco J A, Vetrone F, Boyer J C, et al. Visible upconversion of Er~(3+) doped nanocrystalline and bulk Lu2O3 [J]. Opt Mater, 2002, 19: 259-268.
[77] Zhang H X, Kam C H, Zhou Y, et al. Visible up-conversion luminescence in Er~(3+): BaTiO3 nanocrystals [J]. Opt Mater, 2000, 15: 47-50.
[78] Wang X, Kong X G, Shan G Y, et al. Luminescence Spectroscopy and Visible Upconversion Properties of Er~(3+) in ZnO Nanocrystals [J]. J Phys Chem B 2004, 108(48): 18408-18413.
[79] Ghosh P, Oliva J, Rosa E D L, et al. Enhancement of Upconversion Emission of LaPO4:Er@Yb Core-Shell Nanoparticles/ Nanorods [J]. J Phys Chem C 2008, 112(26): 9650-9658.
[80] Strohh?fer C, Polman A. Relationship between gain and Yb~(3+) concentration in Er~(3+)–Yb~(3+) doped waveguide amplifiers [J]. J Appl Phys, 2001, 90(9): 4314-4320.
[81] Oliveira A S, raujo de M T, Gouveia-Neto A S. Frequency upconversion in Er~(3+)/Yb~(3+)-codoped chalcogenide glass [J]. Appl Phys Lett, 1998, 72(7): 753-755.
[82] Sun Y J, Chen Y, Tian L J, et al. Controlled synthesis and morphology dependent upconversion luminescence of NaYF_4:Yb, Er nanocrystals [J]. Nanotechnology, 2007, 18: 275609 (9pp).
[83] Ghosh P, Patra A. Tuning of Crystal Phase and Luminescence Properties of Eu~(3+) Doped Sodium Yttrium Fluoride Nanocrystals [J]. J Phys Chem C 2008, 112(9): 3223-3231.
[84] Estermann M, Mclusker L B, Baerlocher C, et al. A Synthetic Gallophosphate Molecular-Sieve with a 20- Tetrahedral– Atom Pore Opening [J]. Nature, 1991, 352: 320-323.
[85] Bukovec P, Bukuvel N, Demsar A. Thermal analysis of complex fluorides [J]. J Therm Anal, 1990, 36: 1751-1760.
[86] Zhao C Y, Feng S H, Chao Z C, et al. Hydrothermal synthesis of the complex fluorides LiBaF3 and KMgF3 with perovskite structures under mild conditions [J]. Chem Commun, 1996, 14: 1641-1642.
[87] Sun Y J, Liu H J, Wang X, et al. Optical Spectroscopy and Visible Upconversion Studies of YVO4: Er~(3+) Nanocrystals Synthesized by a Hydrothermal Process [J]. Chem Mater, 2006, 18(11): 2726-2732.
[88] (a) Li C X, Yang J, Yang P P, et al. Two-Dimensionalβ-NaLuF4 Hexagonal Microplates [J]. Cryst Growth Des, 2008, 8(3): 923-929. (b) Li C X, Quan Z W, Yang J, et al. Highly Uniform and Monodisperseβ-NaYF_4:Ln~(3+) (Ln = Eu, Tb, Yb/Er, and Yb/Tm) Hexagonal Microprism Crystals: Hydrothermal Synthesis and Luminescent Properties[J]. Inorg Chem, 2007, 46(16): 6329-9337. (c) Li C X, Quan Z W, Yang P P, et al. Shape controllable synthesis and upconversion properties of NaYbF4/NaYbF4:Er~(3+) and YbF3/YbF3:Er~(3+) microstructures [J]. J Mater Chem, 2008, 18: 1353-1361.
[89] Lin-Vien D, et al. The Handbook of IR and Raman Characteristic Frequencies of Organic Molecules [M]. Academic Press: New York, 1991; p137.
[90] Socrates G. Infrared Characteristic Group Frequencies [M]. Wiley: New York, 1980.
[91] Wang Y, Wong J F, Teng X W, et al.“Pulling”Nanoparticles into Water: Phase Transfer of Oleic Acid Stabilized Monodisperse Nanoparticles into Aqueous Solutions ofα-Cyclodextrin [J]. Nano Lett, 2003, 3(11): 1555-1559.
[92] Jun Y W, Jung Y Y, Cheon J. Architectural Control of Magnetic Semiconductor Nanocrystals [J]. J Am Chem Soc, 2002, 124(4): 615-619.
[93] Jun Y W, Choi J S, Cheon J. Shape Control of Semiconductor and Metal Oxide Nanocrystals through Nonhydrolytic Colloidal Routes [J]. Angew Chem Int Ed, 2006, 45: 3414-3439.
[94] Vayssieres L, Beermann N, Lindquist S E, et al. Controlled Aqueous Chemical Growth of Oriented Three-Dimensional Crystalline Nanorod Arrays: Application to Iron (III) Oxides [J]. Chem Mater, 2001, 13(2): 233-235.
[95] Mai H X, Zhang Y W, Si R, et al. High-Quality Sodium Rare-Earth Fluoride Nanocrystals: Controlled Synthesis and Optical Properties [J]. J Am Chem Soc, 2006, 128: 6426-6436.
[96] Mathews D M, Ambekar R B, Tyagi K A, et al. High temperature X-ray diffraction studies on sodium yttrium fluoride [J]. J Alloys Compd, 2004, 377: 162-166.
[97] McHale J M, Aurous A, Perotta A J, et al. Surface Energies and Thermodynamic Phase Stability in Nanocrystalline Aluminas [J]. Science, 1997, 277 : 788-791.
[98] Zhang H Z, Banfield J F. Thermodynamic analysis of phase stability of nanocrystalline titania [J]. J Mater Chem, 1998, 8(9) : 2073-2076.
[99] Zhang H Z, Gilbert B, Huang F, et al. Water-driven structure transformation in nanoparticles at room temperature [J]. Nature, 2003, 424 : 1025-1029.
[100] Tian Z R, Voigt J A, Liu J, et al. Complex and oriented ZnO nanostructures [J]. Nat Mater, 2003, 2: 821-826.
[101] Pollnau M, Gamelin D R, Lüthi S R, et al. Power dependence of upconversion luminescence in lanthanide and transition-metal-ion systems [J]. Phys Rev B 2000, 61: 3337-3346.
[102] Schmidt T, Müller G, Spanhel L. Activation of 1.54μm Er~(3+) Fluorescence in Concentrated II-VI Semiconductor Cluster Environments [J]. Chem Mater, 1998, 10(1): 65-71.
[103] Vetrone F, Christopher Boyer J, Capobianco J A. Significance of Yb~(3+) concentration on the upconversion mechanisms in codoped Y2O3: Er~(3+), Yb~(3+) nanocrystals [J]. J Appl Phys, 2004, 96(1): 661-667.
[104] Golding P S, Jackson S D, King T A, et al. Energy transfer processes in Er~(3+)-doped and Er~(3+), Pr~(3+)-codoped ZBLAN glasses [J]. Phys Rev B 2000, 62(2): 856–864.
[105] Xiong L Q, Chen Z G, Tian Q W, et al. High contrast upconversion luminescence targeted imaging in vivo using peptide-labeled nanophosphors [J]. Anal Chem, 2009, 81(21): 8687-8694.
[106] Wang F, Chatterjee D K, Li Z Q, et al. Synthesis of polyethylenimine/NaYF_4 nanoparticles with upconversion fluorescence [J]. Nanotechnology, 2006, 17: 5786-5791.
[107] Zhang F, Shi Y F, Sun X H, et al. Formation of Hollow Upconversion Rare-Earth Fluoride Nanospheres: Nanoscale Kirkendall Effect During Ion Exchange [J]. Chem Mater, 2009, 21(21): 5237-5243.
[108] Lou X W, Wang Y, Yuan C, et al. Template-Free Synthesis of SnO_2 Hollow Nanostructures with High Lithium Storage Capacity [J]. Adv Mater, 2006, 18: 2325-2329.
[109] (a) Geng J, Liu B, Xu L, et al. Facile Route to Zn-Based II-VI Semiconductor Spheres, Hollow Spheres, and Core/Shell Nanocrystals and Their Optical Properties [J]. Langmuir, 2007, 23(20): 10286–10293; (b) Hosein I D, Liddell C M. Homogeneous, Core-Shell, and Hollow-Shell ZnS Colloid-Based Photonic Crystals [J]. Langmuir, 2007, 23(5): 2892-2897.
[110] Yin X M, Li C C, Zhang M, et al. SnO_2 monolayer porous hollow spheres as a gas sensor [J]. Nanotechnology, 2009, 20(45): 455503 (6pp).
[111] (a) Li J, Zeng H C. Hollowing Sn-Doped TiO_2 Nanospheres via Ostwald Ripening [J]. J Am Chem Soc, 2007, 129: 15839–15847; (b) Yang Z, Niu Z, Lu Y, et al. Templated Synthesis of Inorganic Hollow Spheres with a Tunable Cavity Size onto Core–Shell Gel Particles [J]. Angew Chem Int Ed, 2003, 42: 1943-1945.
[112] Wang J X, Sun X W, Yang Y, et al. N-P transition sensing behaviors of ZnO nanotubes exposed to NO_2 gas [J]. Nanotechnology, 2009, 20(46): 465501 (4pp).
[113] Yu D, Sun X, Zou J, et al. Oriented Assembly of Fe3O4 Nanoparticles into Monodisperse Hollow Single-Crystal Microspheres [J]. J Phys Chem B 2006, 110(43): 21667-21671.
[114] Jiang W Q, Cao Z, Gu R, et al. A simple route to synthesize ZnFe2O4 hollow spheres and their magnetorheological characteristics [J]. Smart Mater Struct, 2009, 18: 125013 (4pp).
[115] Wang W S, Zhen L, Xu C Y, et al. Aqueous Solution Synthesis of CaF2 Hollow Microspheres via the Ostwald Ripening Process at Room Temperature [J]. ACS Applied Materials & Interfaces, 2009, 1(4): 780–788.
[116] Yamaguchi I, Watanabe M, Shinagawa T, et al. Preparation of Core/Shell and Hollow Nanostructures of Cerium Oxide by Electrodeposition on a Polystyrene Sphere Template [J]. ACS Applied Materials & Interfaces 2009, 1(5): 1070- 1075.
[117] Caruso F, Caruso R A, M?hwald H. Nanoengineering of inorganic and hybrid hollow spheres by colloidal templating [J]. Science, 1998, 282(5391): 1111-1114.
[118] Kim S W, Kim M, Lee W Y, et al. Fabrication of hollow palladium spheres and their successful application to the recyclable heterogeneous catalyst for Suzuki coupling reactions [J]. J Am Chem Soc, 2002, 124(26): 7642-7643.
[119] Liang H, Zhang H, Hu J, et al. Pt Hollow Nanospheres: Facile Synthesis and Enhanced Electrocatalysts [J]. Angew Chem Int Ed, 2004, 43(12): 1540-1543.
[120] Putlitz B Z, Landfester K, Fischer H, et al. The Generation of“Armored Latexes”and Hollow Inorganic Shells Made of Clay Sheets by Templating Cationic Miniemulsions and Latexes [J]. Adv Mater, 2001, 13(7): 500-503.
[121] Bao J, Liang Y, Xu Z, et al. Facile Synthesis of Hollow Nickel Submicrometer Spheres [J]. Adv Mater, 2003, 15(21): 1832-1835.
[122] Zhang D, Qi L, Ma J, et al. Synthesis of Submicrometer-Sized Hollow Silver Spheres in Mixed Polymer-Surfactant Solutions [J]. Adv Mater, 2002, 14: 1499-1502.
[123] Peng Q, Dong Y J, Li Y D. ZnSe Semiconductor Hollow Microspheres [J]. Angew Chem Int Ed, 2003, 42: 3027–3030.
[124] Lou X W, Yuan C L, Rhoades E, et al. Encapsulation and Ostwald Ripening of Au and Au–Cl Complex Nanostructures in Silica Shells [J]. Adv Funct Mater, 2006, 16: 1679-1684.
[125] Wang L Y, Bao J, Wang L, et al. One-Pot Synthesis and Bioapplication of Amine-Functionalized Magnetite Nanoparticles and Hollow Nanospheres [J]. Chem Eur J, 2006, 12(24): 6341–6347.
[126] Yin Y D, Rioux R M, Erdonmez C K, et al. Formation of Hollow Nanocrystals Through the Nanoscale Kirkendall Effect [J]. Science, 2004, 304(5671): 711-714.
[127] Yang H G, Zeng H C. Preparation of Hollow Anatase TiO_2 Nanospheres via Ostwald Ripening [J]. J Phys Chem B 2004, 108(11): 3492-3495.
[128] Xiong Y J, Wiley B, Chen J Y, et al. Corrosion-Based Synthesis of Single-Crystal Pd Nanoboxes and Nanocages and Their Surface Plasmon Properties [J]. Angew Chem Int Ed, 2005, 44: 7913-7917.
[129] Liu Q, Liu H, Han M, et al. Nanometer-Sized Nickel Hollow Spheres [J]. Adv Mater, 2005, 17: 1995-1999.
[130] Zhang H G, Zhu Q S, Zhang Y, et al. One-Pot Synthesis and Hierarchical Assembly of Hollow Cu2O Microspheres with Nanocrystals-Composed Porous Multishell and Their Gas-Sensing Properties [J]. Adv Funct Mater, 2007, 17: 2766–2771.
[131] Gao J H, Zhang B, Zhang X X, et al. Magnetic-Dipolar-Interaction-Induced Self- Assembly Affords Wires of Hollow Nanocrystals of Cobalt Selenide [J]. Angew Chem Int Ed, 2006, 45: 1220– 1223.
[132] (a) Sing K S W, Everett D H, Haul R A W, et al. Reporting physisorption data for gas/solid systems—with special reference to the determination of surface area and porosity [J]. Pure Appl Chem, 1985, 57(4): 603-619; (b) Kondo Y, Yoshikawa H, Awaga K, et al. Preparation, Photocatalytic Activities, and Dye-Sensitized Solar-Cell Performance of Submicron-Scale TiO_2 Hollow Spheres [J]. Langmuir, 2008, 24(2): 547-550.
[133] Yu J, Yu X. Hydrothermal Synthesis and Photocatalytic Activity of Zinc Oxide Hollow Spheres [J]. Environ Sci Technol, 2008, 42(13): 4902-4907.
[134] Yu J G, Wang G H, Cheng B, et al. Effects of hydrothermal temperature and time on the photocatalytic activity and microstructures of bimodal mesoporous TiO_2 powders [J]. Appl Catal B 2007, 69:171-180.
[135] (a) Chang Y, Teo J J, Zeng H C. Formation of Colloidal CuO Nanocrystallites and Their Spherical Aggregation and Reductive Transformation to Hollow Cu2O Nanospheres [J]. Langmuir, 2005, 21(3): 1074–1079; (b) Liu B, Zeng H C. Symmetric and Asymmetric Ostwald Ripening in the Fabrication of Homogeneous Core–Shell Semiconductors [J]. Small, 2005, 1(5): 566-571.
[136] (a) C?lfen H, Antonietti M. Mesocrystals: Inorganic Superstructures Made by Highly Parallel Crystallization and Controlled Alignment [J]. Angew Chem Int Ed, 2005, 44: 5576–5591; (b) C?lfen H, Mann S. Higher-Order Organization by Mesoscale Self-Assembly and Transformation of Hybrid Nanostructures [J]. Angew Chem Int Ed, 2003, 42: 2350–2365; (c) Peng Y, Xu A W, Deng B, et al. Polymer-Controlled Crystallization of Zinc Oxide Hexagonal Nanorings and Disks [J]. J. Phys. Chem. B 2006, 110(7): 2988-2993.
[137] (a) Seigfreid M J, Choi K S. Directing the Architecture of Cuprous Oxide Crystals duringElectrochemical Growth [J]. Angew Chem Int Ed, 2005, 44:3218–3223; (b) Seigfreid M J, Choi K S. Electrochemical Crystallization of Cuprous Oxide with Synthetematic Shape Evolution [J]. Adv Mater, 2004, 16(19): 1743-1746.
[138] Wang F, Liu X G. Upconversion Multicolor Fine-Tuning: Visible to Near-Infrared Emission from Lanthanide-Doped NaYF_4 Nanoparticles [J]. J Am Chem Soc, 2008, 130: 5642–5643.
[139] Mann S, Archibald D D, Didymus J M, et al. Crystallization at Inorganic-organic Interfaces: Biominerals and Biomimetic Synthesis [J]. Science 1993, 261: 1286-1292.
[140] Li Y P, Zhang J H, Zhang X, et al. Near-Infrared to Visible Upconversion in Er~(3+) and Yb~(3+) Codoped Lu2O3 Nanocrystals: Enhanced Red Color Upconversion and Three-Photon Process in Green Color Upconversion [J]. J Phys Chem C 2009, 113(11): 4413-4418.
[141] Suyver J F, Grimm J, Kr?mer K W, et al. Highly efficient near-infraredto visible up-conversion process in NaYF_4: Er~(3+); Yb~(3+) [J]. J Lumin, 2005, 114: 53-59.
[142] Sun C J, Xu Z H, Hu B, et al. Application of NaYF_4: Yb, Er upconversion fluorescence nanocrystals for solution-processed near infrared photodetectors [J]. Appl Phys Lett, 2007, 91: 191113(3pp).
[143] Abdul Jalil R, Zhang Y. Biocompatibility of silica coated NaYF_4 upconversion fluorescent nanocrystals [J]. Biomaterials, 2008, 29: 4122-4128.
[144] Heer S, Lehmann O, Haase M, et al. Blue, Green, and Red Upconversion Emission from Lanthanide-Doped LuPO4 and YbPO4 Nanocrystals in a Transparent Colloidal Solution [J]. Angew Chem Int Ed, 2003, 42(27): 3179-3182.
[145] Zhang F, Wan Y, Yu T, et al. Uniform Nanostructured Arrays of Sodium Rare-Earth Fluorides for Highly Efficient Multicolor Upconversion Luminescence [J]. Angew Chem Int Ed, 2007, 46: 7976-7979.
[146] Liu X M, Zhao J W, Sun Y J, et al. Ionothermal synthesis of hexagonal-phase NaYF_4:Yb~(3+), Er~(3+)/Tm~(3+) upconversion nanophosphors [J]. Chem Commun, 2009, 43: 6628-6630.
[147] Wang F, Liu X G. Recent advances in the chemistry of lanthanide-doped upconversion nanocrystals [J]. Chem Soc Rev, 2009, 4: 976-994.
[148] Wang L Y, Yan R X, Hao Z Y, et al. Fluorescence Resonant Energy Transfer Biosensor Based on Upconversion-Luminescent Nanoparticles [J]. Angew Chem Int Ed, 2005, 44:6054-6057.
[149] Li Z Q, Zhang Y. Monodisperse Silica-Coated Polyvinylpyrrolidone/NaYF_4 Nanocrystals with Multicolor Upconversion Fluorescence Emission [J]. Angew Chem Int Ed, 2006, 45: 7732-7735.
[150] Li W J, Shi E W, Fukuda T. Particle size of powders under hydrothermal conditions [J]. Cryst Res Technol, 2003, 38(10): 847-858.
[151] Kobayashi S, Hiroishi K, Tokunoh M, et al. Chelating Properties of Linear and Branched Poly(ethylenimines) [J]. Macromolecules, 1987, 20(7): 1496-1500.
[152] Xiong J Y, Liu X Y, Sawant P D, et al. Surfactant free fabrication of polymeric nanoparticles by combined liquid-liquid phase separation and solvent/nonsolvent mixing technology [J]. J Chem Phys, 2004, 121(24): 12616-12631.
[153] Zhao J W, Sun Y J, Kong X G, et al. Controlled Synthesis, Formation Mechanism, and Great Enhancement of Red Upconversion Luminescence of NaYF_4:Yb~(3+), Er~(3+) Nanocrystals/Submicroplates at Low Doping Level [J]. J Phys Chem B 2008, 112(49): 15666-15672.
[154] Wang Y, Tu L P, Zhao J W, et al. Upconversion Luminescence ofβ-NaYF_4: Yb~(3+), Er~(3+) @β-NaYF_4 Core/Shell Nanoparticles: Excitation Power Density and Surface Dependence [J]. J Phys Chem C 2009, 113(17): 7164–7169
[155] Babaean, Pivamik R, Leteher S, et al. Evaluation of antibody immobilization methods for Piezoelectric biosensor application [J]. Biosens Bioelectron, 2000, 15(11-12): 615- 621.
[156] Ballulekar R, Ayyangar N R, Ponrathnam S. Polyethyleneimine in immobilization of bioeatalysts [J]. Enzyme Microb Technol, 1991, 13(11) : 858-868.
[157] Bakef A, Saltik M, Lehrmann H, et al. Polyethylenimine(PEI) is a simple, inexpensive and effective reagent for condensing and linking plasmid DNA to adenovirus for gene delivery [J]. Gene Ther, 1997, 4(8) : 773-782.
[158] Kircheis R, Wightman L, Wagner E. Design and gene delivery activity of modified polyethylenimines[J]. Adv Drug Deliv Rev, 2001, 53(3) : 341-358.
[159] Lvov Y, Ariga K, Ichinose I, et al. Assembly of multicomponent protein films by means of electrostatic layer-by-layer adsorption[J]. J Am Chem Soc, 1995, 117(22) : 6117-6123.
[160] Boussif O, Lezoualeh F, Zanta M A, et al. A versatile vector for gene and oligonucleotide transfer into cells in culture and in-vivo-Polyethylenimine [J]. Proc Natl Acad Sci U S A, 1995, 92(16) : 7297-7301.
[161] Thomas M, Ge Q, Lu J J, et al. Cross-linked small polyethylenimines: While still nontoxic, deliver DNA efficiently to manunalian cells in vitro and in vivo [J]. Pharm Res, 2005, 22(3): 373-380.
[2]张志焜,崔作林.纳米技术与纳米材料[M],北京:国防工业出版社,2000.
[3]顾宁,付德刚,张海黔.纳米技术及应用[M],北京:人民邮电出版社,2002.
[4]杨志伊.纳米科技[M],北京:机械工业出版社,2004.
[5]薛增泉.纳米电子学[J],现代科学仪器,1998,1-2:8-12.
[6]薛群基,徐康.纳米化学[J],化学进展,2000,12(4):431-444.
[7]温诗铸.纳米摩擦学[J],北京:清华大学出版社,1998.
[8]陈慧文,容敏智,章明秋.分子与纳米自组装材料的研究进展[J],材料导报,2002:16(8):59-61.
[9] Feynman R P. There is plenty of room at the bottom, Lecture at the annual meeting of the American Physical Society at the California Institute of Technology[R]. 1959.
[10]周瑞发,韩雅芳,陈祥宝.纳米材料技术[M],北京:国防工业出版社,2003.
[11] Yu S H, Bio-inspired Crystal Growth by Synthetic Templates [J]. Top Curr Chem, 2007, 271: 79-118.
[12] Cushing B L, Kolesnichenko V L, O’Connor C J. Recent Advances in the Liquid-Phase Syntheses of Inorganic Nanoparticles [J]. Chem. Rev, 2004, 104: 3893-3946
[13] Smigelskas A D, Kirkendall E O. Zinc Diffusion in Alpha Brass [J]. Trans. AIME, 1947, 171: 130-142.
[14]全国第一届溶胶-凝胶会议论文集“特种玻璃”[C],1990, 7: 3.
[15] Wong E M, Bonevich J E, Searson P C. The growth kinetics of nanocrystalline ZnO particles from colloidal suspensions [J]. J Phys Chem B, 1998, 102: 7770-7775.
[16] Lakshmi B B, Dorhout P K, Martin C R. Sol-gel template synthesis of semiconductor nanostructures [J]. Chem Mater, 1997, 9: 857-862.
[17] Gu F, Wang S F, Lu M K, et al. Photoluminescence properties of SnO_2 nanoparticles synthesized by sol-gel method [J]. J Phys Chem B, 2004, 108: 8119-8123.
[18] You H P, Nogami M. Optical Properties and Local Structure of Eu~(3+) Ions in Sol?Gel TiO_2?SiO_2 Glasses [J]. J Phys Chem B, 2004, 108: 12003-12008.
[19] Ptatschek V, Schreder B, Herz K, et al. Sol-Gel Synthesis and Spectroscopic Properties of Thick Nanocrystalline CdSe Films [J]. J Phys Chem B, 1997, 101: 8898-8906.
[20] Gacoin T, Huignard A, Counio G, et al. Chemical Design of Nanostructured Luminescent Materials [J]. Mater Res Soc Symp Pro, 2000, 62.
[21]林君,苏锵,溶胶-凝胶法及其在稀土发光材料合成中的应用[J].稀土学报,1994, 1(15): 42-46.
[22]石士考,霍庆.无机粉末发光材料合成的新方法[J].无机盐工业,1999,31:20-22.
[23]王惠琴.4SrO·7A12O3: Eu发光材料的快速合成及X-射线衍射分析[J].发光学报, 1996,17 (增刊):72-73.
[24] Hoar T P, Schulman J H. Transparent Water-in-Oil Dispersions: the Oleopathic Hydro-Micelle [J]. Nature, 1943, 152:102-103.
[25] Schulman J H, Stoeckenius W, Prince L M. Mechanism of Formation and Structure of Microemulsions by Electron Microscopy [J]. J Phys Chem, 1959, 63(10), 1677-1680.
[26] Stevens M J, Robbins M O. Density Functional Theory of Ionic Screening: When Do Like Charges Attract? [J]. Europhys Lett, 1990, 12(1): 81-86.
[27] Mitchell D J, Ninham B W. Micelles, vesicles and microemulsions [J]. J Chem Soc Faraday Trans, 1981, 77: 601-629.
[28] Attard P, Mitchell D J, Ninham B W. Beyond Poisson-Boltzmann: Images and correlations in the electric double layer. I. Counterions only [J]. J Chem Phys, 1988, 88(8): 4987-4996.
[29]刘应亮,石春山.Eu~(3+)在xMF2-yYF3体系中光谱性质及其变化规律[J].发光学报,1990,11:22-28.
[30] Mai H X, Zhang Y W, Si R, et al. High-Quality Sodium Rare-Earth Fluoride Nanocrystals: Controlled Synthesis and Optical Properties [J]. J Am Chem Soc, 2006, 128: 6426-6436.
[31] Yi G S, Chow G M. Synthesis of Hexagonal-Phase NaYF_4: Yb, Er and NaYF_4:Yb, Tm Nanocrystals with Efficient Up-Conversion Fluorescence[J]. Adv Funct Mater, 2006, 16: 2324-2329.
[32] (a) Jun Y W, Lee J H, Choi J S, et al. Symmetry-Controlled Colloidal Nanocrystals: Nonhydrolytic Chemical Synthesis and Shape Determining Parameters[J]. J. Phys. Chem. B, 2005, 109: 14795-14806; (b) Burda C, Chen X B, Narayanan R, et al. Chemistry and properties of nanocrystals of different shapes [J]. Chem Rev, 2005, 105(4): 1025-1102.
[33]仲维卓,华素坤.晶体生长形态学[M].科学出版社.1999.
[34] Hong B H, Bae S C, Lee C W, et al. Ultrathin single-crystalline silver nanowire arrays formed in an ambient solution phase [J]. Science, 2001, 294(5541): 348-351.
[35] Puntes V F, Krishnan K M, Alivisatos A P. Colloidal nanocrystal shape and size control: The case of cobalt [J]. Science, 2001, 291(5511): 2115-2117.
[36] Peng X G. Mechanisms for the shape-control and shape-evolution of colloidal semiconductor nanocrystals [J]. Adv Mater, 2003, 15(5): 459-463.
[37]孙家跃,杜海燕.无机材料制造与应用[M].北京:化学工业出版社,2001.
[38] (a) Auzel F. Acad Sci (Paris) [Z]. 1966, 262:1016-1019. (b) Auzel F, Acad Sci(Paris) [Z]. 1966, 263: 819-821.
[39] Stephens R R, McFarlane R A. Diode-pumped upconversion laser with 100-mW output power [J]. Opt Lett, 1993, 18 (1): 34-36.
[40] Auzel F. Upconversion and Anti-Stokes Processes with f and d Ions in Solids [J]. Chem Rev, 2004, 104 (1): 139-174.
[41]张思远,毕宪章.稀土光谱理论[M].吉林科学技术出版社,1991.
[42]张立德,牟季美.开拓原子和物质的中间领域—纳米微粒与纳米固体[J].物理学报,1992,21,167-173.
[43] Stephens R R, Mc Farlane R A. Diode-pumped upconversion laser with 100-mW output power [J]. Opt Lett, 1993, 18(1): 34-36.
[44] Mo C, Yuan Z, Zhang L, et al. Infrared absorption spectra of nano-alumina [J]. Nanostructured Materials, 1993, 2(1): 47-54.
[45]蔡树芝,牟季美,张立德等.物理学报[J],1992,41:1620.
[46] Tabagi H, Ogawa H, Yamazaki Y, et al. Quantum size effects on photoluminescence in ultratfne Si particles [J]. Appl Phys Lett, 1990, 56: 2379-2380.
[47] Brus L. Squeezing light from silicon [J]. Nature, 1991, 353: 301-302.
[48] Heine F, Heumann E, Danger T, et al. Green upconversion continuous wave Er~(3+): LiYF_4 laser at room temperature [J]. Appl Phys Lett, 1994, 65(4): 383-384.
[49] Tanabe S, Hayashi H, Hanada T, et al. Fluorescence properties of Er~(3+) ions in glass ceramics containing LaF3 nanocrystals [J]. Optical Materials, 2002, 19(3): 343-349.
[50] Hampl J, Hall M, Mufti N A, et al. Up-converting phosphor reporters in immunochromatographic assays [J]. Analytical Biochemistry, 2001, 288: 176-187.
[51] Niedbala R S, Feindt H, Kardos K, et al. Detection of analytes by immunoassay using up-converting phosphor technology [J]. Analytical Biochemistry, 2001, 293: 22-30.
[52] Zijlmans H J M A A, Bonnet J, Burton J, et al. Detection of cell and tissue surface antigens using upconverting phosopors: a new reports technology [J]. Anal Biochem, 1999, 267: 30-36.
[53] Lim S F, Riehn R, Ryu W S, et al. In Vivo and Scanning Electron Microscopy Imaging of Upconverting Nanophosphors in Caenorhabditis elegans [J]. Nano Lett, 2006, 6(2):169-174.
[54] Corstjens P, Zuiderwijk M, Brink A, et al. Use of upconverting phosphor reporters in lateral-flow assays to detect specific nucleic acid sequences: a rapid, sensitive DNA test to identify human papillomavirus type 16 infection [J]. Clinical Chem, 2001, 47: 1885-1893.
[55] van de Rijke F, Zijlmans H, Li S, et al. Upconverting phosphor reports for nucleic acid microarrays [J]. Nature Biotech, 2001, 19: 273-276.
[56] Zhang P, Steelant W, Kumar M, et al. Versatile Photosensitizers for hotodynamic Therapy at Infrared Excitation [J]. J Am Chem Soc, 2007, 129: 4526-4527.
[57] Kr?mer K W, Biner D, Frei G, et al. Hexagonal Sodium Yttrium Fluoride Based Green and Blue Emitting Upconversion Phosphors [J]. Chem Mater, 2004, 16(7): 1244-1251.
[58] Menyuk N, Dwight K, Pierce J W. NaYF_4: Yb, Er– an efficient upconversion phosphor [J]. Appl Phys Lett, 1972, 21(4): 159-161.
[59] Suyver J F, Grimm J, van Veen M K, et al. Upconversion spectroscopy and properties of NaYF_4 doped with Er~(3+), Tm~(3+) and/or Yb~(3+) [J]. J Lumin, 2006, 117: 1-12.
[60] Yi G S, Chow G M. Synthesis of Hexagonal-Phase NaYF_4:Yb,Er and NaYF_4:Yb,Tm Nanocrystals with Efficient Up-Conversion Fluorescence [J]. Adv Funct Mater, 2006, 16: 2324-2329.
[61] Heer S, K?mpe K, Güdel H U, et al. Highly Efficient Multicolour Upconversion Emission in Transpatent Colloids of Lanthanide-Doped NaYF_4 Nanocrystals [J]. Adv Mater, 2004, 16: 2102-2105.
[62] Zeng J H, Su J, Li Z H, et al. Synthesis and Upconversion Luminescence of Hexagonal-Phase NaYF_4:Yb,Er Phosphors of Controlled Size and Morphology [J]. Adv Mater, 2005, 17, 2119-2123.
[63] Yi G S, Lu H C, Zhao S Y, et al. Synthesis, Characterization, and Biological Application of Size-Controlled Nanocrystalline NaYF_4: Yb, Er Infrared-to-Visible Up-Conversion Phosphors [J]. Nano Lett, 2004, 4(11): 2191-2196.
[64] Sch?fer H, Ptacek P, K?mpe K, et al. Lanthanide-Doped NaYF_4 Nanocrystals in Aqueous Solution Displaying Strong Up-Conversion Emission [J]. Chem Mater, 2007, 19(6): 1396-1400.
[65] Wang L Y, Li Y D. Controlled Synthesis and Luminescence of Lanthanide Doped NaYF_4 Nanocrystals [J]. Chem Mater, 2007, 19(4): 727-734.
[66] Wang L Y, Li Y D. Green upconversion nanocrystals for DNA detection [J]. Chem Commun, 2006, 24: 2557-2559.
[67] Chan W C W, Nie S M. Quantum dot bioconjugates for ultrasensitive nonisotopic detection [J]. Science, 1998, 281(5385) : 2016-2018.
[68] Chatterjee D K, Rufaihah A J, Zhang Y. Upconversion fluorescence imaging of cells and small animals using lanthanide doped nanocrystals [J]. Biomaterials 2008, 29: 937-943.
[69] Feijo J A, Moreno N. Imaging plant cells by two-photon excitation [J]. Protoplasma, 2004, 223(1): 1-32.
[70] Patra A, Friend C S, Kapoor R, et al. Upconversion in Er~(3+): ZrO_2 Nanocrystals [J]. J Phys Chem B 2002, 106(8): 1909-1912.
[71] Patra A, Friend C S, Kapoor R, et al. Fluorescence Upconversion Properties of Er~(3+)-Doped TiO_2 and BaTiO3 Nanocrystallites [J]. Chem Mater, 2003, 15(19): 3650-3655.
[72] Vetrone F, Boyer J C, Capobianco J A, et al. Effect of Yb~(3+) Codoping on the Upconversion Emission in Nanocrystalline Y2O3:Er~(3+) [J]. J Phys Chem B 2003, 107(5): 1107-1112.
[73] Stouwdam J W, van Veggel F C J M. Near-infrared Emission of Redispersible Er~(3+), Nd~(3+), and Ho~(3+) Doped LaF3 Nanoparticles [J]. Nano Lett, 2002, 2(7), 733-737.
[74] Vetrone F, Christopher Boyer J, Capobianco J A, et al. Concentration-Dependent Near-Infrared to Visible Upconversion in Nanocrystalline and Bulk Y2O3:Er~(3+) [J]. Chem Mater, 2003, 15(14): 2737-2743.
[75] Vetrone F, Christopher Boyer J, Capobianco J A. NIR to Visible Upconversion in Nanocrystalline and Bulk Lu2O3:Er~(3+) [J]. J Phys Chem B 2002, 106(22): 5622-5628.
[76] Capobianco J A, Vetrone F, Boyer J C, et al. Visible upconversion of Er~(3+) doped nanocrystalline and bulk Lu2O3 [J]. Opt Mater, 2002, 19: 259-268.
[77] Zhang H X, Kam C H, Zhou Y, et al. Visible up-conversion luminescence in Er~(3+): BaTiO3 nanocrystals [J]. Opt Mater, 2000, 15: 47-50.
[78] Wang X, Kong X G, Shan G Y, et al. Luminescence Spectroscopy and Visible Upconversion Properties of Er~(3+) in ZnO Nanocrystals [J]. J Phys Chem B 2004, 108(48): 18408-18413.
[79] Ghosh P, Oliva J, Rosa E D L, et al. Enhancement of Upconversion Emission of LaPO4:Er@Yb Core-Shell Nanoparticles/ Nanorods [J]. J Phys Chem C 2008, 112(26): 9650-9658.
[80] Strohh?fer C, Polman A. Relationship between gain and Yb~(3+) concentration in Er~(3+)–Yb~(3+) doped waveguide amplifiers [J]. J Appl Phys, 2001, 90(9): 4314-4320.
[81] Oliveira A S, raujo de M T, Gouveia-Neto A S. Frequency upconversion in Er~(3+)/Yb~(3+)-codoped chalcogenide glass [J]. Appl Phys Lett, 1998, 72(7): 753-755.
[82] Sun Y J, Chen Y, Tian L J, et al. Controlled synthesis and morphology dependent upconversion luminescence of NaYF_4:Yb, Er nanocrystals [J]. Nanotechnology, 2007, 18: 275609 (9pp).
[83] Ghosh P, Patra A. Tuning of Crystal Phase and Luminescence Properties of Eu~(3+) Doped Sodium Yttrium Fluoride Nanocrystals [J]. J Phys Chem C 2008, 112(9): 3223-3231.
[84] Estermann M, Mclusker L B, Baerlocher C, et al. A Synthetic Gallophosphate Molecular-Sieve with a 20- Tetrahedral– Atom Pore Opening [J]. Nature, 1991, 352: 320-323.
[85] Bukovec P, Bukuvel N, Demsar A. Thermal analysis of complex fluorides [J]. J Therm Anal, 1990, 36: 1751-1760.
[86] Zhao C Y, Feng S H, Chao Z C, et al. Hydrothermal synthesis of the complex fluorides LiBaF3 and KMgF3 with perovskite structures under mild conditions [J]. Chem Commun, 1996, 14: 1641-1642.
[87] Sun Y J, Liu H J, Wang X, et al. Optical Spectroscopy and Visible Upconversion Studies of YVO4: Er~(3+) Nanocrystals Synthesized by a Hydrothermal Process [J]. Chem Mater, 2006, 18(11): 2726-2732.
[88] (a) Li C X, Yang J, Yang P P, et al. Two-Dimensionalβ-NaLuF4 Hexagonal Microplates [J]. Cryst Growth Des, 2008, 8(3): 923-929. (b) Li C X, Quan Z W, Yang J, et al. Highly Uniform and Monodisperseβ-NaYF_4:Ln~(3+) (Ln = Eu, Tb, Yb/Er, and Yb/Tm) Hexagonal Microprism Crystals: Hydrothermal Synthesis and Luminescent Properties[J]. Inorg Chem, 2007, 46(16): 6329-9337. (c) Li C X, Quan Z W, Yang P P, et al. Shape controllable synthesis and upconversion properties of NaYbF4/NaYbF4:Er~(3+) and YbF3/YbF3:Er~(3+) microstructures [J]. J Mater Chem, 2008, 18: 1353-1361.
[89] Lin-Vien D, et al. The Handbook of IR and Raman Characteristic Frequencies of Organic Molecules [M]. Academic Press: New York, 1991; p137.
[90] Socrates G. Infrared Characteristic Group Frequencies [M]. Wiley: New York, 1980.
[91] Wang Y, Wong J F, Teng X W, et al.“Pulling”Nanoparticles into Water: Phase Transfer of Oleic Acid Stabilized Monodisperse Nanoparticles into Aqueous Solutions ofα-Cyclodextrin [J]. Nano Lett, 2003, 3(11): 1555-1559.
[92] Jun Y W, Jung Y Y, Cheon J. Architectural Control of Magnetic Semiconductor Nanocrystals [J]. J Am Chem Soc, 2002, 124(4): 615-619.
[93] Jun Y W, Choi J S, Cheon J. Shape Control of Semiconductor and Metal Oxide Nanocrystals through Nonhydrolytic Colloidal Routes [J]. Angew Chem Int Ed, 2006, 45: 3414-3439.
[94] Vayssieres L, Beermann N, Lindquist S E, et al. Controlled Aqueous Chemical Growth of Oriented Three-Dimensional Crystalline Nanorod Arrays: Application to Iron (III) Oxides [J]. Chem Mater, 2001, 13(2): 233-235.
[95] Mai H X, Zhang Y W, Si R, et al. High-Quality Sodium Rare-Earth Fluoride Nanocrystals: Controlled Synthesis and Optical Properties [J]. J Am Chem Soc, 2006, 128: 6426-6436.
[96] Mathews D M, Ambekar R B, Tyagi K A, et al. High temperature X-ray diffraction studies on sodium yttrium fluoride [J]. J Alloys Compd, 2004, 377: 162-166.
[97] McHale J M, Aurous A, Perotta A J, et al. Surface Energies and Thermodynamic Phase Stability in Nanocrystalline Aluminas [J]. Science, 1997, 277 : 788-791.
[98] Zhang H Z, Banfield J F. Thermodynamic analysis of phase stability of nanocrystalline titania [J]. J Mater Chem, 1998, 8(9) : 2073-2076.
[99] Zhang H Z, Gilbert B, Huang F, et al. Water-driven structure transformation in nanoparticles at room temperature [J]. Nature, 2003, 424 : 1025-1029.
[100] Tian Z R, Voigt J A, Liu J, et al. Complex and oriented ZnO nanostructures [J]. Nat Mater, 2003, 2: 821-826.
[101] Pollnau M, Gamelin D R, Lüthi S R, et al. Power dependence of upconversion luminescence in lanthanide and transition-metal-ion systems [J]. Phys Rev B 2000, 61: 3337-3346.
[102] Schmidt T, Müller G, Spanhel L. Activation of 1.54μm Er~(3+) Fluorescence in Concentrated II-VI Semiconductor Cluster Environments [J]. Chem Mater, 1998, 10(1): 65-71.
[103] Vetrone F, Christopher Boyer J, Capobianco J A. Significance of Yb~(3+) concentration on the upconversion mechanisms in codoped Y2O3: Er~(3+), Yb~(3+) nanocrystals [J]. J Appl Phys, 2004, 96(1): 661-667.
[104] Golding P S, Jackson S D, King T A, et al. Energy transfer processes in Er~(3+)-doped and Er~(3+), Pr~(3+)-codoped ZBLAN glasses [J]. Phys Rev B 2000, 62(2): 856–864.
[105] Xiong L Q, Chen Z G, Tian Q W, et al. High contrast upconversion luminescence targeted imaging in vivo using peptide-labeled nanophosphors [J]. Anal Chem, 2009, 81(21): 8687-8694.
[106] Wang F, Chatterjee D K, Li Z Q, et al. Synthesis of polyethylenimine/NaYF_4 nanoparticles with upconversion fluorescence [J]. Nanotechnology, 2006, 17: 5786-5791.
[107] Zhang F, Shi Y F, Sun X H, et al. Formation of Hollow Upconversion Rare-Earth Fluoride Nanospheres: Nanoscale Kirkendall Effect During Ion Exchange [J]. Chem Mater, 2009, 21(21): 5237-5243.
[108] Lou X W, Wang Y, Yuan C, et al. Template-Free Synthesis of SnO_2 Hollow Nanostructures with High Lithium Storage Capacity [J]. Adv Mater, 2006, 18: 2325-2329.
[109] (a) Geng J, Liu B, Xu L, et al. Facile Route to Zn-Based II-VI Semiconductor Spheres, Hollow Spheres, and Core/Shell Nanocrystals and Their Optical Properties [J]. Langmuir, 2007, 23(20): 10286–10293; (b) Hosein I D, Liddell C M. Homogeneous, Core-Shell, and Hollow-Shell ZnS Colloid-Based Photonic Crystals [J]. Langmuir, 2007, 23(5): 2892-2897.
[110] Yin X M, Li C C, Zhang M, et al. SnO_2 monolayer porous hollow spheres as a gas sensor [J]. Nanotechnology, 2009, 20(45): 455503 (6pp).
[111] (a) Li J, Zeng H C. Hollowing Sn-Doped TiO_2 Nanospheres via Ostwald Ripening [J]. J Am Chem Soc, 2007, 129: 15839–15847; (b) Yang Z, Niu Z, Lu Y, et al. Templated Synthesis of Inorganic Hollow Spheres with a Tunable Cavity Size onto Core–Shell Gel Particles [J]. Angew Chem Int Ed, 2003, 42: 1943-1945.
[112] Wang J X, Sun X W, Yang Y, et al. N-P transition sensing behaviors of ZnO nanotubes exposed to NO_2 gas [J]. Nanotechnology, 2009, 20(46): 465501 (4pp).
[113] Yu D, Sun X, Zou J, et al. Oriented Assembly of Fe3O4 Nanoparticles into Monodisperse Hollow Single-Crystal Microspheres [J]. J Phys Chem B 2006, 110(43): 21667-21671.
[114] Jiang W Q, Cao Z, Gu R, et al. A simple route to synthesize ZnFe2O4 hollow spheres and their magnetorheological characteristics [J]. Smart Mater Struct, 2009, 18: 125013 (4pp).
[115] Wang W S, Zhen L, Xu C Y, et al. Aqueous Solution Synthesis of CaF2 Hollow Microspheres via the Ostwald Ripening Process at Room Temperature [J]. ACS Applied Materials & Interfaces, 2009, 1(4): 780–788.
[116] Yamaguchi I, Watanabe M, Shinagawa T, et al. Preparation of Core/Shell and Hollow Nanostructures of Cerium Oxide by Electrodeposition on a Polystyrene Sphere Template [J]. ACS Applied Materials & Interfaces 2009, 1(5): 1070- 1075.
[117] Caruso F, Caruso R A, M?hwald H. Nanoengineering of inorganic and hybrid hollow spheres by colloidal templating [J]. Science, 1998, 282(5391): 1111-1114.
[118] Kim S W, Kim M, Lee W Y, et al. Fabrication of hollow palladium spheres and their successful application to the recyclable heterogeneous catalyst for Suzuki coupling reactions [J]. J Am Chem Soc, 2002, 124(26): 7642-7643.
[119] Liang H, Zhang H, Hu J, et al. Pt Hollow Nanospheres: Facile Synthesis and Enhanced Electrocatalysts [J]. Angew Chem Int Ed, 2004, 43(12): 1540-1543.
[120] Putlitz B Z, Landfester K, Fischer H, et al. The Generation of“Armored Latexes”and Hollow Inorganic Shells Made of Clay Sheets by Templating Cationic Miniemulsions and Latexes [J]. Adv Mater, 2001, 13(7): 500-503.
[121] Bao J, Liang Y, Xu Z, et al. Facile Synthesis of Hollow Nickel Submicrometer Spheres [J]. Adv Mater, 2003, 15(21): 1832-1835.
[122] Zhang D, Qi L, Ma J, et al. Synthesis of Submicrometer-Sized Hollow Silver Spheres in Mixed Polymer-Surfactant Solutions [J]. Adv Mater, 2002, 14: 1499-1502.
[123] Peng Q, Dong Y J, Li Y D. ZnSe Semiconductor Hollow Microspheres [J]. Angew Chem Int Ed, 2003, 42: 3027–3030.
[124] Lou X W, Yuan C L, Rhoades E, et al. Encapsulation and Ostwald Ripening of Au and Au–Cl Complex Nanostructures in Silica Shells [J]. Adv Funct Mater, 2006, 16: 1679-1684.
[125] Wang L Y, Bao J, Wang L, et al. One-Pot Synthesis and Bioapplication of Amine-Functionalized Magnetite Nanoparticles and Hollow Nanospheres [J]. Chem Eur J, 2006, 12(24): 6341–6347.
[126] Yin Y D, Rioux R M, Erdonmez C K, et al. Formation of Hollow Nanocrystals Through the Nanoscale Kirkendall Effect [J]. Science, 2004, 304(5671): 711-714.
[127] Yang H G, Zeng H C. Preparation of Hollow Anatase TiO_2 Nanospheres via Ostwald Ripening [J]. J Phys Chem B 2004, 108(11): 3492-3495.
[128] Xiong Y J, Wiley B, Chen J Y, et al. Corrosion-Based Synthesis of Single-Crystal Pd Nanoboxes and Nanocages and Their Surface Plasmon Properties [J]. Angew Chem Int Ed, 2005, 44: 7913-7917.
[129] Liu Q, Liu H, Han M, et al. Nanometer-Sized Nickel Hollow Spheres [J]. Adv Mater, 2005, 17: 1995-1999.
[130] Zhang H G, Zhu Q S, Zhang Y, et al. One-Pot Synthesis and Hierarchical Assembly of Hollow Cu2O Microspheres with Nanocrystals-Composed Porous Multishell and Their Gas-Sensing Properties [J]. Adv Funct Mater, 2007, 17: 2766–2771.
[131] Gao J H, Zhang B, Zhang X X, et al. Magnetic-Dipolar-Interaction-Induced Self- Assembly Affords Wires of Hollow Nanocrystals of Cobalt Selenide [J]. Angew Chem Int Ed, 2006, 45: 1220– 1223.
[132] (a) Sing K S W, Everett D H, Haul R A W, et al. Reporting physisorption data for gas/solid systems—with special reference to the determination of surface area and porosity [J]. Pure Appl Chem, 1985, 57(4): 603-619; (b) Kondo Y, Yoshikawa H, Awaga K, et al. Preparation, Photocatalytic Activities, and Dye-Sensitized Solar-Cell Performance of Submicron-Scale TiO_2 Hollow Spheres [J]. Langmuir, 2008, 24(2): 547-550.
[133] Yu J, Yu X. Hydrothermal Synthesis and Photocatalytic Activity of Zinc Oxide Hollow Spheres [J]. Environ Sci Technol, 2008, 42(13): 4902-4907.
[134] Yu J G, Wang G H, Cheng B, et al. Effects of hydrothermal temperature and time on the photocatalytic activity and microstructures of bimodal mesoporous TiO_2 powders [J]. Appl Catal B 2007, 69:171-180.
[135] (a) Chang Y, Teo J J, Zeng H C. Formation of Colloidal CuO Nanocrystallites and Their Spherical Aggregation and Reductive Transformation to Hollow Cu2O Nanospheres [J]. Langmuir, 2005, 21(3): 1074–1079; (b) Liu B, Zeng H C. Symmetric and Asymmetric Ostwald Ripening in the Fabrication of Homogeneous Core–Shell Semiconductors [J]. Small, 2005, 1(5): 566-571.
[136] (a) C?lfen H, Antonietti M. Mesocrystals: Inorganic Superstructures Made by Highly Parallel Crystallization and Controlled Alignment [J]. Angew Chem Int Ed, 2005, 44: 5576–5591; (b) C?lfen H, Mann S. Higher-Order Organization by Mesoscale Self-Assembly and Transformation of Hybrid Nanostructures [J]. Angew Chem Int Ed, 2003, 42: 2350–2365; (c) Peng Y, Xu A W, Deng B, et al. Polymer-Controlled Crystallization of Zinc Oxide Hexagonal Nanorings and Disks [J]. J. Phys. Chem. B 2006, 110(7): 2988-2993.
[137] (a) Seigfreid M J, Choi K S. Directing the Architecture of Cuprous Oxide Crystals duringElectrochemical Growth [J]. Angew Chem Int Ed, 2005, 44:3218–3223; (b) Seigfreid M J, Choi K S. Electrochemical Crystallization of Cuprous Oxide with Synthetematic Shape Evolution [J]. Adv Mater, 2004, 16(19): 1743-1746.
[138] Wang F, Liu X G. Upconversion Multicolor Fine-Tuning: Visible to Near-Infrared Emission from Lanthanide-Doped NaYF_4 Nanoparticles [J]. J Am Chem Soc, 2008, 130: 5642–5643.
[139] Mann S, Archibald D D, Didymus J M, et al. Crystallization at Inorganic-organic Interfaces: Biominerals and Biomimetic Synthesis [J]. Science 1993, 261: 1286-1292.
[140] Li Y P, Zhang J H, Zhang X, et al. Near-Infrared to Visible Upconversion in Er~(3+) and Yb~(3+) Codoped Lu2O3 Nanocrystals: Enhanced Red Color Upconversion and Three-Photon Process in Green Color Upconversion [J]. J Phys Chem C 2009, 113(11): 4413-4418.
[141] Suyver J F, Grimm J, Kr?mer K W, et al. Highly efficient near-infraredto visible up-conversion process in NaYF_4: Er~(3+); Yb~(3+) [J]. J Lumin, 2005, 114: 53-59.
[142] Sun C J, Xu Z H, Hu B, et al. Application of NaYF_4: Yb, Er upconversion fluorescence nanocrystals for solution-processed near infrared photodetectors [J]. Appl Phys Lett, 2007, 91: 191113(3pp).
[143] Abdul Jalil R, Zhang Y. Biocompatibility of silica coated NaYF_4 upconversion fluorescent nanocrystals [J]. Biomaterials, 2008, 29: 4122-4128.
[144] Heer S, Lehmann O, Haase M, et al. Blue, Green, and Red Upconversion Emission from Lanthanide-Doped LuPO4 and YbPO4 Nanocrystals in a Transparent Colloidal Solution [J]. Angew Chem Int Ed, 2003, 42(27): 3179-3182.
[145] Zhang F, Wan Y, Yu T, et al. Uniform Nanostructured Arrays of Sodium Rare-Earth Fluorides for Highly Efficient Multicolor Upconversion Luminescence [J]. Angew Chem Int Ed, 2007, 46: 7976-7979.
[146] Liu X M, Zhao J W, Sun Y J, et al. Ionothermal synthesis of hexagonal-phase NaYF_4:Yb~(3+), Er~(3+)/Tm~(3+) upconversion nanophosphors [J]. Chem Commun, 2009, 43: 6628-6630.
[147] Wang F, Liu X G. Recent advances in the chemistry of lanthanide-doped upconversion nanocrystals [J]. Chem Soc Rev, 2009, 4: 976-994.
[148] Wang L Y, Yan R X, Hao Z Y, et al. Fluorescence Resonant Energy Transfer Biosensor Based on Upconversion-Luminescent Nanoparticles [J]. Angew Chem Int Ed, 2005, 44:6054-6057.
[149] Li Z Q, Zhang Y. Monodisperse Silica-Coated Polyvinylpyrrolidone/NaYF_4 Nanocrystals with Multicolor Upconversion Fluorescence Emission [J]. Angew Chem Int Ed, 2006, 45: 7732-7735.
[150] Li W J, Shi E W, Fukuda T. Particle size of powders under hydrothermal conditions [J]. Cryst Res Technol, 2003, 38(10): 847-858.
[151] Kobayashi S, Hiroishi K, Tokunoh M, et al. Chelating Properties of Linear and Branched Poly(ethylenimines) [J]. Macromolecules, 1987, 20(7): 1496-1500.
[152] Xiong J Y, Liu X Y, Sawant P D, et al. Surfactant free fabrication of polymeric nanoparticles by combined liquid-liquid phase separation and solvent/nonsolvent mixing technology [J]. J Chem Phys, 2004, 121(24): 12616-12631.
[153] Zhao J W, Sun Y J, Kong X G, et al. Controlled Synthesis, Formation Mechanism, and Great Enhancement of Red Upconversion Luminescence of NaYF_4:Yb~(3+), Er~(3+) Nanocrystals/Submicroplates at Low Doping Level [J]. J Phys Chem B 2008, 112(49): 15666-15672.
[154] Wang Y, Tu L P, Zhao J W, et al. Upconversion Luminescence ofβ-NaYF_4: Yb~(3+), Er~(3+) @β-NaYF_4 Core/Shell Nanoparticles: Excitation Power Density and Surface Dependence [J]. J Phys Chem C 2009, 113(17): 7164–7169
[155] Babaean, Pivamik R, Leteher S, et al. Evaluation of antibody immobilization methods for Piezoelectric biosensor application [J]. Biosens Bioelectron, 2000, 15(11-12): 615- 621.
[156] Ballulekar R, Ayyangar N R, Ponrathnam S. Polyethyleneimine in immobilization of bioeatalysts [J]. Enzyme Microb Technol, 1991, 13(11) : 858-868.
[157] Bakef A, Saltik M, Lehrmann H, et al. Polyethylenimine(PEI) is a simple, inexpensive and effective reagent for condensing and linking plasmid DNA to adenovirus for gene delivery [J]. Gene Ther, 1997, 4(8) : 773-782.
[158] Kircheis R, Wightman L, Wagner E. Design and gene delivery activity of modified polyethylenimines[J]. Adv Drug Deliv Rev, 2001, 53(3) : 341-358.
[159] Lvov Y, Ariga K, Ichinose I, et al. Assembly of multicomponent protein films by means of electrostatic layer-by-layer adsorption[J]. J Am Chem Soc, 1995, 117(22) : 6117-6123.
[160] Boussif O, Lezoualeh F, Zanta M A, et al. A versatile vector for gene and oligonucleotide transfer into cells in culture and in-vivo-Polyethylenimine [J]. Proc Natl Acad Sci U S A, 1995, 92(16) : 7297-7301.
[161] Thomas M, Ge Q, Lu J J, et al. Cross-linked small polyethylenimines: While still nontoxic, deliver DNA efficiently to manunalian cells in vitro and in vivo [J]. Pharm Res, 2005, 22(3): 373-380.