基于Ag/Si-NPA的DNA碱基高灵敏度SERS探测
|
摘要
以硅纳米孔柱阵列(Si-NPA)为衬底,采用浸渍还原法制备了一种图案化的硅基银纳米结构(Ag/Si-NPA).以Ag/Si-NPA为表面增强拉曼散射(SERS)的活性基底,实现了对鸟嘌呤、胞嘧啶和胸腺嘧啶三种DNA碱基的低浓度探测.结果表明,三种DNA碱基分子均通过羰基和氮原子倾斜吸附于Ag/Si-NPA表面且吸附位点类似,但倾斜角略有不同.随着溶液浓度的降低,碱基分子更趋向平行吸附于基底表面.由此证明,Ag/Si-NPA可以显著增强DNA碱基分子的拉曼散射效应,是一种可用于低浓度生物分子检测的性能优异的SERS活性基底.
A regularly patterned silver nanostructure(Ag/Si-NPA) was prepared by an immersion plating method on the template of silicon nanoporous pillar array(Si-NPA). Using Ag/Si-NPA as active substrates,the adsorption behavior of three DNA bases(guanine,cytosine,and thymine) at low concentration was studied by surface-enhanced Raman scattering(SERS) technique. Based on the obtained SERS spectra,it was deduced that the three DNA bases were all slightly tilted adsorbed on the surface of the silver particles but with different inclination angles. The adsorption sites for different bases were similar: all through carbonyl group and nitrogen atom. With reducing concentration,the planes of the base molecules were all tend to be parallel to the surface of substrate. The results suggested that the Raman spectra of DNA bases could be significantly enhanced when adsorbed on the surface of Ag/Si-NPA,and it might be an effective SERS active substrate for the detection of low-concentration bio-molecules.
A regularly patterned silver nanostructure(Ag/Si-NPA) was prepared by an immersion plating method on the template of silicon nanoporous pillar array(Si-NPA). Using Ag/Si-NPA as active substrates,the adsorption behavior of three DNA bases(guanine,cytosine,and thymine) at low concentration was studied by surface-enhanced Raman scattering(SERS) technique. Based on the obtained SERS spectra,it was deduced that the three DNA bases were all slightly tilted adsorbed on the surface of the silver particles but with different inclination angles. The adsorption sites for different bases were similar: all through carbonyl group and nitrogen atom. With reducing concentration,the planes of the base molecules were all tend to be parallel to the surface of substrate. The results suggested that the Raman spectra of DNA bases could be significantly enhanced when adsorbed on the surface of Ag/Si-NPA,and it might be an effective SERS active substrate for the detection of low-concentration bio-molecules.
引文
[1]许海军,富笑男,孙新瑞,等.硅纳米孔柱阵列的结构和光学特性研究[J].物理学报,2005,54(5):2352-2357.
[2] XU H J,LI X J. Silicon nanoporous pillar array:a silicon hierarchical structure with high light absorption and triple-band photoluminescence[J]. Opt Express,2008,16(5):2933-2941.
[3] FENG F,ZHI G,JIA H S,et al. SERS detection of low-concentration adenine by a patterned silver structure immersion plated on a silicon nanoporous pillar array[J]. Nanotechnology,2009,20(29):295501.
[4] WANG Y Q,MA S,YANG Q Q,et al. Size-dependent SERS detection of R6G by silver nanoparticles immersion-plated on silicon nanoporous pillar array[J]. Appl Surf Sci,2012,258(15):5881-5885.
[5] LI X J,HU X,JIA Y,et al. Tunable superstructures in hydrothermally etched iron-passivated porous silicon[J]. Appl Phys Lett,1999,75(19):2906-2908.
[6] GIESE B,MCNAUGHTON D. Density functional theoretical(DFT)and surface-enhanced Raman spectroscopic study of guanine and its alkylated derivatives[J]. Phys Chem Chem Phys,2002,4(20):5171-5182.
[7] MOSKOVITS M,SUH J S. Surface selection rules for surface-enhanced Raman spectroscopy:calculations and application to the surface-enhanced Raman spectrum of phthalazine on silver[J]. J Phys Chem,1984,88(23):5526-5530.
[8] CAMAFEITA E,SNCHEZ-CORTS S,GARCA-RAMOS J V. SERS of cytosine and its methylated derivatives on gold sols[J]. J Raman Spectrosc,1995,26(2):149-154.
[9] LIU S,ZHENG G,LI J. Raman spectral study of metal-cytosine complexes:a density functional theoretical(DFT)approach[J].Spectrochim Acta A,2011,79(5):1739-1746.
[10] ATAKA K,OSAWA M. In situ infrared study of cytosine adsorption on gold electrodes[J]. J Electroanal Chem,1999,460(1/2):188-196.
[11] SHANG Z G,TING D N,WONG Y T,et al. A study of DFT and surface enhanced Raman scattering in silver colloids for thymine[J]. J Mol Struct,2007,826(1):64-67.
[12] CHO K H,CHOO J,JOO S W. Tautomerism of thymine on gold and silver nanoparticle surfaces:surface-enhanced Raman scattering and density functional theory calculation study[J]. J Mol Struct,2005,738(1/2/3):9-14.
[13] GAO X,DAVIES J P,WEAVER M J. A test of surface selection rules for surface-enhanced Raman scattering:the orientation of adsorbed benzene and monosubstituted benzenes on gold[J]. J Phys Chem,1990,94(17):6858-6864.
[2] XU H J,LI X J. Silicon nanoporous pillar array:a silicon hierarchical structure with high light absorption and triple-band photoluminescence[J]. Opt Express,2008,16(5):2933-2941.
[3] FENG F,ZHI G,JIA H S,et al. SERS detection of low-concentration adenine by a patterned silver structure immersion plated on a silicon nanoporous pillar array[J]. Nanotechnology,2009,20(29):295501.
[4] WANG Y Q,MA S,YANG Q Q,et al. Size-dependent SERS detection of R6G by silver nanoparticles immersion-plated on silicon nanoporous pillar array[J]. Appl Surf Sci,2012,258(15):5881-5885.
[5] LI X J,HU X,JIA Y,et al. Tunable superstructures in hydrothermally etched iron-passivated porous silicon[J]. Appl Phys Lett,1999,75(19):2906-2908.
[6] GIESE B,MCNAUGHTON D. Density functional theoretical(DFT)and surface-enhanced Raman spectroscopic study of guanine and its alkylated derivatives[J]. Phys Chem Chem Phys,2002,4(20):5171-5182.
[7] MOSKOVITS M,SUH J S. Surface selection rules for surface-enhanced Raman spectroscopy:calculations and application to the surface-enhanced Raman spectrum of phthalazine on silver[J]. J Phys Chem,1984,88(23):5526-5530.
[8] CAMAFEITA E,SNCHEZ-CORTS S,GARCA-RAMOS J V. SERS of cytosine and its methylated derivatives on gold sols[J]. J Raman Spectrosc,1995,26(2):149-154.
[9] LIU S,ZHENG G,LI J. Raman spectral study of metal-cytosine complexes:a density functional theoretical(DFT)approach[J].Spectrochim Acta A,2011,79(5):1739-1746.
[10] ATAKA K,OSAWA M. In situ infrared study of cytosine adsorption on gold electrodes[J]. J Electroanal Chem,1999,460(1/2):188-196.
[11] SHANG Z G,TING D N,WONG Y T,et al. A study of DFT and surface enhanced Raman scattering in silver colloids for thymine[J]. J Mol Struct,2007,826(1):64-67.
[12] CHO K H,CHOO J,JOO S W. Tautomerism of thymine on gold and silver nanoparticle surfaces:surface-enhanced Raman scattering and density functional theory calculation study[J]. J Mol Struct,2005,738(1/2/3):9-14.
[13] GAO X,DAVIES J P,WEAVER M J. A test of surface selection rules for surface-enhanced Raman scattering:the orientation of adsorbed benzene and monosubstituted benzenes on gold[J]. J Phys Chem,1990,94(17):6858-6864.