NIR Emission Nanoparticles Based on FRET Composed of AIE Luminogens and NIR Dyes for Two-photon Fluorescence Imaging
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摘要
Near-infrared(NIR) nanoparticles(NPs) based on fluorescence resonance energy transfer(FRET) were prepared by coencapsulation of a red aggregation-induced emission(AIE) molecule, 2-(4-bromophenyl)-3-(4-(4-(diphenylamino)styryl)phenyl)fumaronitrile(TB), and a commercial NIR fluorescence dye, silicon 2,3-naphthalocyanine bis(trihexylsilyloxide)(NIR775) with an amphiphilic polymer poly(styrene-co-maleic anhydride)(PSMA). The surface of the NPs, PSMA@TB/NIR775, was modified with poly(ethylene glycol)(PEG) to increase the in vivo biocompatibility of the NPs. The PSMA@TB/NIR775 NPs showed a strong NIR(780 nm) narrow emission and excellent two-photon absorption property. Moreover, the NPs exhibited good monodispersity, stability, and low cytotoxicity.Under the excitation of a 1040 nm femtosecond(fs) laser, the emission peaks at 680 nm of TB and 780 nm of NIR775 excited by FRET were obtained. We utilized PSMA@TB/NIR775 NPs as fluorescent contrast agents for two-photon excited NIR microscopic imaging, and good NIR imaging effect of mouse brain vasculature was obtained with the imaging depth of about 150 μm. The FRET strategy by coencapsulating AIE molecule and NIR dye will be helpful in preparing more narrow emission NIR probes for deep-tissue biological imaging.
Near-infrared(NIR) nanoparticles(NPs) based on fluorescence resonance energy transfer(FRET) were prepared by coencapsulation of a red aggregation-induced emission(AIE) molecule, 2-(4-bromophenyl)-3-(4-(4-(diphenylamino)styryl)phenyl)fumaronitrile(TB), and a commercial NIR fluorescence dye, silicon 2,3-naphthalocyanine bis(trihexylsilyloxide)(NIR775) with an amphiphilic polymer poly(styrene-co-maleic anhydride)(PSMA). The surface of the NPs, PSMA@TB/NIR775, was modified with poly(ethylene glycol)(PEG) to increase the in vivo biocompatibility of the NPs. The PSMA@TB/NIR775 NPs showed a strong NIR(780 nm) narrow emission and excellent two-photon absorption property. Moreover, the NPs exhibited good monodispersity, stability, and low cytotoxicity.Under the excitation of a 1040 nm femtosecond(fs) laser, the emission peaks at 680 nm of TB and 780 nm of NIR775 excited by FRET were obtained. We utilized PSMA@TB/NIR775 NPs as fluorescent contrast agents for two-photon excited NIR microscopic imaging, and good NIR imaging effect of mouse brain vasculature was obtained with the imaging depth of about 150 μm. The FRET strategy by coencapsulating AIE molecule and NIR dye will be helpful in preparing more narrow emission NIR probes for deep-tissue biological imaging.
Near-infrared(NIR) nanoparticles(NPs) based on fluorescence resonance energy transfer(FRET) were prepared by coencapsulation of a red aggregation-induced emission(AIE) molecule, 2-(4-bromophenyl)-3-(4-(4-(diphenylamino)styryl)phenyl)fumaronitrile(TB), and a commercial NIR fluorescence dye, silicon 2,3-naphthalocyanine bis(trihexylsilyloxide)(NIR775) with an amphiphilic polymer poly(styrene-co-maleic anhydride)(PSMA). The surface of the NPs, PSMA@TB/NIR775, was modified with poly(ethylene glycol)(PEG) to increase the in vivo biocompatibility of the NPs. The PSMA@TB/NIR775 NPs showed a strong NIR(780 nm) narrow emission and excellent two-photon absorption property. Moreover, the NPs exhibited good monodispersity, stability, and low cytotoxicity.Under the excitation of a 1040 nm femtosecond(fs) laser, the emission peaks at 680 nm of TB and 780 nm of NIR775 excited by FRET were obtained. We utilized PSMA@TB/NIR775 NPs as fluorescent contrast agents for two-photon excited NIR microscopic imaging, and good NIR imaging effect of mouse brain vasculature was obtained with the imaging depth of about 150 μm. The FRET strategy by coencapsulating AIE molecule and NIR dye will be helpful in preparing more narrow emission NIR probes for deep-tissue biological imaging.
引文
1 Yan, L. L.; Zhang, Y.; Ji,G.; Ma, L.; Chen, J. L.; Xu,B.; Tian,W. J. Multifunctional polymer nanoparticles, ultra bright nearinfrared fluorescence and strong magnetization and their biological applications. RSC Adv. 2016, 6, 65426-65433.
2 Ji, G.; Yan, L. L.; Wang, H.; Ma, L.; Xu, B.; Tian, W. J. Efficient near-infrared AIE nanoparticles for cell imaging. Acta Chimica Sinica(in Chinese)2016, 74, 917-922.
3 Zhang,F. L.; Di,Y. Z.; Li,Y.; Qi,Q. K.; Qian,J. Y.; Fu,X. Q.;Xu, B.; Tian, W. J. Highly efficient far red/near-infrared fluorophores with aggregation-induced emission for bioimaging.Dyes Pigments 2017, 142, 491-498.
4 Kobat, D.; Horton, N. G.; Xu, C. In vivo two-photon microscopy to 1.6-mm depth in mouse cortex. J. Biomed. Opt. 2011,16, 106014.
5 Qian, J.; Wang, D.; Cai, F. H.; Zhan, Q. Q.; Wang, Y. L.; He,S. L. Photosensitizer encapsulated organically modified silica nanoparticles for direct two-photon photodynamic therapy and in vivo functional imaging. Biomaterials 2012, 33, 4851-4860.
6 Lakowicz, J. R. Plasmonics in biology and plasmon-controlled fluorescence. Plasmonics 2006, 1, 5-33.
7 Hinds, S.; Myrskog, S.; Levina, L.; Koleilat, G.; Yang, J.; Kelley, S. O.; Sargent, E. H. NIR-emitting colloidal quantum dots having 26%luminescence quantum yield in buffer solution. J.Am. Chem. Soc. 2007, 129, 7218-7219.
8 Yong,K. T.; Roy,I.; Ding,H.; Bergey,E. J.; Prasad, P. N.Biocompatible near-infrared quantum dots as ultrasensitive probes for long-term in vivo imaging applications. Small 2009,5, 1997-2004.
9 Dabbousi, B. O.; Rodriguez-Viejo, J.; Mikulec, F. V.; Heine, J.R.; Mattoussi, H.; Ober, R.; Jensen, K. F.; Bawendi, M. G.(CdSe)ZnS core-shell quantum dots:Synthesis and characterization of a size series of highly luminescent nanocrystallites. J.Phys. Chem. B 1997, 101, 9463-9475.
10 Shi,L. J.; Zhu,C. N.; He, H.; Zhu,D. L.; Zhang,Z. L.; Pang,D. W.; Tian, Z. Q. Near-infrared Ag2Se quantum dots with distinct absorption features and high fluorescence quantum yields.RSC Adv. 2016, 6, 38183-38186.
11 Wu, C. X.; Zhang, Y. J.; Li, Z.; Li, C. Y.; Wang, Q. B. A novel photoacoustic nanoprobe of ICG@PEG-Ag2S for atherosclero-sis targeting and imaging in vivo. Nanoscale 2016, 8,12531-12539.
12 Han, H. J.; Wang, H. B.; Chen, Y. J.; Li, Z. H.; Wang, Y.; Jin,Q.; Ji, J. Theranostic reduction-sensitive gemcitabine prodrug micelles for near-infrared imaging and pancreatic cancer therapy. Nanoscale 2016, 8, 283-291.
13 Luo, S. L.; Zhang, E. L.; Su, Y. P.; Cheng,T. M.; Shi,C. M. A review of NIR dyes in cancer targeting and imaging. Biomaterials 2011,32, 7127-7138.
14 Gao, X. H.; Yang, L. L.; Petros, J. A.; Marshal, F. F.; Simons,J. W.; Nie, S. M. In vivo molecular and cellular imaging with quantum dots. Curr. Opin. Biotechnol. 2005, 16, 63-72.
15 Escobedo, J. O.; Rusin, O.; Lim, S.; Strongin, R. M. NIR dyes for bioimaging applications. Curr. Opin. Chem. Biol. 2010, 14,64-70.
16 Thomas, S. W.; Joly, G. D.; Swager, T. M. Chemical sensors based on amplifying fluorescent conjugated polymers. Chem.Rev. 2007, 107, 1339-1386.
17 Brasseur, N.; Nguyen, T. L.; Langlois, R.; Ouellet, R.; Marengo, S.; Houde, D.; van Lier, J. E. Synthesis and photodynamic activities of silicon 2,3-naphthalocyanine derivatives. J. Med.Chem. 1994,37,415-420.
18 Birks, J. B. in Photophysics of aromatic molecules, Wiley, London, UK, 1970.
19 Tang, B. Z.; Zhan, X.; Yu, G.; Lee, P.; Liu, Y.; Zhu, D. B. Efficient blue emission from siloles. J. Mater. Chem. 2001, 11,2974-2978.
20 Luo, J. D.; Xie, Z. L.; Lam, J. W. Y.; Cheng, L.; Chen, H. Y.;Qiu, C. F.; Kwok, H. S.; Zhan, X. W.; Liu, Y. Q.; Zhu, D. B.;Tang,B. Z. Aggregation-induced emission of 1-methyl-1,2,3,4,5-pentaphenylsilole. Chem. Commun. 2001, 1740-1741.
21 Hong, Y. N.; Lam, J. W. Y.; Tang, B. Z. Aggregation-induced emission, phenomenon, mechanism and applications. Chem.Commun. 2009, 4332-4353.
22 Mei,J.; Hong,Y. N.; Lam,J. W. Y.; Qin,A. J.; Tang,Y. H.;Tang, B. Z. Aggregation-induced emission:The whole is more brilliant than the parts. Adv. Mater. 2014, 26, 5429-5479.
23 Ding, D.; Li, K.; Liu, B.; Tang, B. Z. Bioprobes based on AIE fluorogens. Acc. Chem. Res. 2013, 46, 2441-2453.
24 Hong, Y. N.; Lam, J. W. Y.; Tang, B. Z. Aggregation-induced emission. Chem. Soc. Rev. 2011, 40, 5361-5388.
25 Mei,J.; Leung, N. L. C.; Kwok,R. T. K.; Lam,J. W. Y.; Tang,B. Z. Aggregation-induced emission:Together we shine, united we soar! Chem. Rev. 2015, 115, 11718-11940.
26 Zhang,X. Y.; Wang,K.; Liu,M. Y.; Zhang,X. Q.; Tao, L.;Chen, Y. W.; Wei, Y. Polymeric AIE-based nanoprobes for biomedical applications:Recent advances and perspectives.Nanoscale 2015, 7, 11486-11508.
27 Yan, L. L.; Zhang, Y.; Xu, B.; Tian, W. J. Fluorescent nanoparticles based on AIE fluorogens for bioimaging. Nanoscale2016, 8, 2471-2487.
28 Zhang, Y.; Chen, Y. J.; Li, X.; Zhang, J. B.; Chen, J. L.; Xu, B.;Fu, X. Q.; Tian, W. J. Folic acid-functionalized AIE Pdots based on amphiphilic PCL-b-PEG for targeted cell imaging.Polym. Chem. 2014, 5, 3824-3830.
29 Zhang, X. Q.; Zhang, X. Y.; Wang, S. Q.; Liu, M. Y.; Tao, L.;Wei, Y. Surfactant modification of aggregation-induced emission material as biocompatible nanoparticles:Facile preparation and cell imaging. Nanoscale 2013, 5, 147-150.
30 Qin,W.; Ding,D.; Liu,J. Z.; Yuan,W. Z.; Hu,Y.; Liu,B.;Tang, B. Z. Biocompatible nanoparticles with aggregation-induced emission characteristics as far-red/near-infrared fluorescent bioprobes for in vitro and in vivo imaging applications.Adv. Funct. Mater. 2012, 22, 771-779.
31 Geng, J. L.; Li, K.; Ding,D.; Zhang, X. H.; Qin,W.; Liu, J. Z.;Tang, B. Z.; Liu, B. Lipid-PEG-folate encapsulated nanoparticles with aggregation induced emission characteristics:Cellular uptake mechanism and two-photon fluorescence ima-ging. Small 2012, 8, 3655-3663.
32 Geng, J. L.; Li, K.; Pu, K. Y.; Ding, D.; Liu, B. Conjugated polymer and gold nanoparticle co-loaded PLGA nanocomposites with eccentric internal nanostructure for dual-modal targeted cellular imaging. Small 2013, 9, 2012-2019.
33 Li, K.; Qin, W.; Ding,D.; Tomczak,N.; Geng, J. L.; Liu,R. R.;Liu, J. Z.; Zhang, X. H.; Liu, H. W.; Liu, B.; Tang, B. Z. Photostable fluorescent organic dots with aggregation-induced emission(AIE dots)for noninvasive long-term cell tracing. Sci.Rep. 2013, 3, 1150.
34 Wang, Z. L.; Yan, L. L.; Zhang, L.; Chen, Y. J.; Li, H.; Zhang,J. B.; Zhang,Y.; Li,X.; Xu,B.; Fu,X. Q.; Sun,Z. C.; Tian,W.J. Ultra bright red AIE dots for cytoplasm and nuclear imaging.Polym. Chem. 2014, 5, 7013-7020.
35 Zhang, Y.; Chang, K. W.; Xu, B.; Chen, J. L.; Yan, L. L.; Ma,S. Q.; Wu, C. F.; Tian, W. J. Highly efficient near-infrared organic dots based on novel AEE fluorogen for specific cancer cell imaging. RSCAdv. 2015, 5, 36837-36844.
36 Wang, L.; Tan, W. H. Multicolor FRET silica nanoparticles by single wavelength excitation. Nano Lett. 2006, 6, 84-88.
37 Zhang, J.; Lakowicz, J. R. A model for DNA detection by metal-enhanced fluorescence from immobilized silver nanoparticles on solid substrate. J. Phys. Chem. B 2006, 110,2387-2392.
38 Jin, Y. H.; Ye, F. M.; Zeigler, M.; Wu, C. F.; Chiu, D. T. Nearinfrared fluorescent dye-doped semiconducting polymer dots.ACS Nano 2011, 5, 1468-1475.
39 Chung, C. Y. S.; Yam, V. W. W. Selective label-free detection of G-quadruplex structure of human telomere by emission spectral changes in visible-and-NIR region under physiological condition through the FRET of a two-component PPE-SO3-Pt(II)complex ensemble with Pt…Pt, electrostatic andπ-πinteractions. Chem. Sci. 2013, 4, 377-387.
40 Zhang,X. J.; Yu,J. B.; Rong,Y.; Ye,F. M.; Chiu,D. T.;Uvdal, K. High-intensity near-IR fluorescence in semiconducting polymer dots achieved by cascade FRET strategy. Chem.Sci. 2013, 4,2143-2151.
41 Wagh, A.; Qian, S. Y.; Law, B. Development of biocompatible polymeric nanoparticles for in vivo NIR and FRET imaging.Bioconjugate Chem. 2012, 23, 981-992.
42 Geng,J. L.; Zhu,Z. S.; Qin,W.; Ma,L.; Hu, Y.; Gurzadyan,G.G.; Tang, B. Z.; Liu, B. Near-infrared fluorescence amplified organic nanoparticles with aggregation-induced emission characteristics for in vivo imaging. Nanoscale 2014, 6, 939-945.
43 Xie,Z. Q.; Yang,B.; Xie,W. J.; Liu,L. L.; Shen,F. Z.; Wang,H. A.; Yang, X. Y.; Wang, Z. M.; Li, Y. P.; Hanif, M.; Yang,G. D.; Ye, L.; Ma, Y. G. A class of nonplanar conjugated compounds with aggregation-induced emission, structural and optical properties of 2,5-diphenyl-1,4-distyrylbenzene derivatives with all cis double bonds. J. Phys. Chem. B 2006, 110,20993-21000.
44 Hong, G. S.; Zou, Y. P.; Antaris, A. L.; Diao, S.; Wu, D.;Cheng, K.; Zhang, X. D.; Chen, C. X.; Liu, B.; He, Y. H.; Wu,J. Z.; Yuan, J.; Zhang, B.; Tao, Z. M.; Fukunaga, C.; Dai, H. J.Ultrafast fluorescence imaging in vivo with conjugated polymer fluorophores in the second near-infrared window. Nat.Commun. 2014, 5, 4206.
45 Rust, M. J.; Bates, M.; Zhuang, X. Sub-diffraction-limit imaging by stochastic optical reconstruction microscopy(STORM). Nat. Methods 2006, 3, 793-795.
46 Betzig,E.; Patterson,G. H.; Sougrat, R.; Lindwasser,O. W.;Olenych, S.; Bonifacino, J. S.; Davidson, M. W.; LippincottSchwartz, J.; Hess, H. F. Imaging intracellular fluorescent proteins at nanometer resolution. Science 2006, 313, 1642-1645.
47 Axelrod, D. Total internal reflection fluorescence microscopy in cell biology. Traffic 2001, 2, 764-774.
48 Chen,B.;Feng,G.X.;He,B.R.;Goh,C.;Xu,S.D.;RamosOrtiz, G.; Aparicio-Ixta, L.; Zhou, J.; Ng, L. G.; Zhao, Z. J.;Liu, B.; Tang, B. Z. Silole-based red fluorescent organic dots for bright two-photon fluorescence in vitro cell and in vivo blood vessel imaging. Small 2016, 12, 782-792.
49 Lou, X. D.; Zhao, Z. J.; Tang, B. Z. Organic dots based on AIEgens for two-photon fluorescence bioimaging. Small 2016,72, 6430-6450.
50 Zhen, S. J.; Wang, S. W.; Li, S. W.; Luo, W. W.; Gao, M.; Ng,L. G.; Goh, C. C.; Qin, A. J.; Zhao, Z. J.; Liu, B.; Tang, B. Z.Efficient red/near-infrared fluorophores based on benzo[1,2-b:4,5-b']dithiophene 1,1,5,5-tetraoxide for targeted photodynamic therapy and in vivo two-photon fluorescence bioimaging.Adv. Funct. Mater. 2018, 28. 1706945.
51 Shen, X. Y.; Yuan, W. Z.; Liu, Y.; Zhao, Q. L.; Lu, P.; Ma, Y.G.; Williams, I. D.; Qin, A. J.; Sun, J. Z.; Tang, B. Z. Fumaronitrile-based fluorogen, red to near-infrared fluorescence, aggregation-induced emission, solvatochromism, and twisted intramolecular charge transfer. J. Phys. Chem. C 2012, 116,10541-10547.
52 Liu, W.; Wang, Y. L; Han, X.; Lu, P.; Zhu, L.; Sun, C. W.; Qian, J.; He, S. L. Fluorescence resonance energy transfer(FRET)based nanoparticles composed of AIE luminogens and NIR dyes with enhanced three-photon near-infrared emission for in vivo brain angiography.. Nanoscale 2018, 10, 10025-10032.
53 Wang, Y.; Hu,R.; Xi,W.; Cai,F.; Wang, S.; Zhu,Z.; Bai,R.;Qian, J. Red emissive AIE nanodots with high two-photon absorption efficiency at 1040 nm for deep-tissue in vivo imaging.Biomed. Opt. Express 2015, 6, 3783-3794.
54 Alifu,N.; Yan,L. L.; Zhang,H. Q.; Zebibula,A.; Zhu,Z. G.;Xi, W.; Roe, A. W.; Xu, B.; Tian, W. J.; Qian, J. Organic dye doped nanoparticles with NIR emission and biocompatibility for ultra-deep in vivo two-photon microscopy under 1040 nm femtosecond excitation. Dyes Pigments 2017, 143, 76-85.
55Han,X.;Bai,Q.;Yao,L.;Liu,H.C.;Gao,Y.;Li,J.Y.;Liu,L.Q.; Liu, Y. L.; Li,X. X.; Lu,P.; Yang, B. Highly efficient solid-state near-infrared emitting material based on triphenylamine and diphenylfumaronitrile with an EQE of 2.58%in nondoped organic light-emitting diode. Adv. Funt. Mater. 2015,25, 7521-7529.
56 Zhu, Z. F.; Qian, J.; Zhao, X. Y.; Qin, W.; Hu, R. R.; Zhang, H.Q.; Li, D. Y.; Xu, Z. P.; Tang, B. Z.; He, S. L. Stable and sizetunable aggregation-induced emission nanoparticles encapsulated with nanographene oxide and applications in three-photon fluorescence bioimaging. ACS Nano 2016, 10. 588-597.
57 Lakowicz,J. R. in Principles of fluorescence spectroscopy,Springer, Berlin,3rd ed.,2006.
58 Polavarapu, L.; Manna, M.; Xu, Q. H. Biocompatible glutathione capped gold clusters as one-and two-photon excitation fluorescence contrast agents for live cells imaging. Nanoscale2011,3, 429-434.
2 Ji, G.; Yan, L. L.; Wang, H.; Ma, L.; Xu, B.; Tian, W. J. Efficient near-infrared AIE nanoparticles for cell imaging. Acta Chimica Sinica(in Chinese)2016, 74, 917-922.
3 Zhang,F. L.; Di,Y. Z.; Li,Y.; Qi,Q. K.; Qian,J. Y.; Fu,X. Q.;Xu, B.; Tian, W. J. Highly efficient far red/near-infrared fluorophores with aggregation-induced emission for bioimaging.Dyes Pigments 2017, 142, 491-498.
4 Kobat, D.; Horton, N. G.; Xu, C. In vivo two-photon microscopy to 1.6-mm depth in mouse cortex. J. Biomed. Opt. 2011,16, 106014.
5 Qian, J.; Wang, D.; Cai, F. H.; Zhan, Q. Q.; Wang, Y. L.; He,S. L. Photosensitizer encapsulated organically modified silica nanoparticles for direct two-photon photodynamic therapy and in vivo functional imaging. Biomaterials 2012, 33, 4851-4860.
6 Lakowicz, J. R. Plasmonics in biology and plasmon-controlled fluorescence. Plasmonics 2006, 1, 5-33.
7 Hinds, S.; Myrskog, S.; Levina, L.; Koleilat, G.; Yang, J.; Kelley, S. O.; Sargent, E. H. NIR-emitting colloidal quantum dots having 26%luminescence quantum yield in buffer solution. J.Am. Chem. Soc. 2007, 129, 7218-7219.
8 Yong,K. T.; Roy,I.; Ding,H.; Bergey,E. J.; Prasad, P. N.Biocompatible near-infrared quantum dots as ultrasensitive probes for long-term in vivo imaging applications. Small 2009,5, 1997-2004.
9 Dabbousi, B. O.; Rodriguez-Viejo, J.; Mikulec, F. V.; Heine, J.R.; Mattoussi, H.; Ober, R.; Jensen, K. F.; Bawendi, M. G.(CdSe)ZnS core-shell quantum dots:Synthesis and characterization of a size series of highly luminescent nanocrystallites. J.Phys. Chem. B 1997, 101, 9463-9475.
10 Shi,L. J.; Zhu,C. N.; He, H.; Zhu,D. L.; Zhang,Z. L.; Pang,D. W.; Tian, Z. Q. Near-infrared Ag2Se quantum dots with distinct absorption features and high fluorescence quantum yields.RSC Adv. 2016, 6, 38183-38186.
11 Wu, C. X.; Zhang, Y. J.; Li, Z.; Li, C. Y.; Wang, Q. B. A novel photoacoustic nanoprobe of ICG@PEG-Ag2S for atherosclero-sis targeting and imaging in vivo. Nanoscale 2016, 8,12531-12539.
12 Han, H. J.; Wang, H. B.; Chen, Y. J.; Li, Z. H.; Wang, Y.; Jin,Q.; Ji, J. Theranostic reduction-sensitive gemcitabine prodrug micelles for near-infrared imaging and pancreatic cancer therapy. Nanoscale 2016, 8, 283-291.
13 Luo, S. L.; Zhang, E. L.; Su, Y. P.; Cheng,T. M.; Shi,C. M. A review of NIR dyes in cancer targeting and imaging. Biomaterials 2011,32, 7127-7138.
14 Gao, X. H.; Yang, L. L.; Petros, J. A.; Marshal, F. F.; Simons,J. W.; Nie, S. M. In vivo molecular and cellular imaging with quantum dots. Curr. Opin. Biotechnol. 2005, 16, 63-72.
15 Escobedo, J. O.; Rusin, O.; Lim, S.; Strongin, R. M. NIR dyes for bioimaging applications. Curr. Opin. Chem. Biol. 2010, 14,64-70.
16 Thomas, S. W.; Joly, G. D.; Swager, T. M. Chemical sensors based on amplifying fluorescent conjugated polymers. Chem.Rev. 2007, 107, 1339-1386.
17 Brasseur, N.; Nguyen, T. L.; Langlois, R.; Ouellet, R.; Marengo, S.; Houde, D.; van Lier, J. E. Synthesis and photodynamic activities of silicon 2,3-naphthalocyanine derivatives. J. Med.Chem. 1994,37,415-420.
18 Birks, J. B. in Photophysics of aromatic molecules, Wiley, London, UK, 1970.
19 Tang, B. Z.; Zhan, X.; Yu, G.; Lee, P.; Liu, Y.; Zhu, D. B. Efficient blue emission from siloles. J. Mater. Chem. 2001, 11,2974-2978.
20 Luo, J. D.; Xie, Z. L.; Lam, J. W. Y.; Cheng, L.; Chen, H. Y.;Qiu, C. F.; Kwok, H. S.; Zhan, X. W.; Liu, Y. Q.; Zhu, D. B.;Tang,B. Z. Aggregation-induced emission of 1-methyl-1,2,3,4,5-pentaphenylsilole. Chem. Commun. 2001, 1740-1741.
21 Hong, Y. N.; Lam, J. W. Y.; Tang, B. Z. Aggregation-induced emission, phenomenon, mechanism and applications. Chem.Commun. 2009, 4332-4353.
22 Mei,J.; Hong,Y. N.; Lam,J. W. Y.; Qin,A. J.; Tang,Y. H.;Tang, B. Z. Aggregation-induced emission:The whole is more brilliant than the parts. Adv. Mater. 2014, 26, 5429-5479.
23 Ding, D.; Li, K.; Liu, B.; Tang, B. Z. Bioprobes based on AIE fluorogens. Acc. Chem. Res. 2013, 46, 2441-2453.
24 Hong, Y. N.; Lam, J. W. Y.; Tang, B. Z. Aggregation-induced emission. Chem. Soc. Rev. 2011, 40, 5361-5388.
25 Mei,J.; Leung, N. L. C.; Kwok,R. T. K.; Lam,J. W. Y.; Tang,B. Z. Aggregation-induced emission:Together we shine, united we soar! Chem. Rev. 2015, 115, 11718-11940.
26 Zhang,X. Y.; Wang,K.; Liu,M. Y.; Zhang,X. Q.; Tao, L.;Chen, Y. W.; Wei, Y. Polymeric AIE-based nanoprobes for biomedical applications:Recent advances and perspectives.Nanoscale 2015, 7, 11486-11508.
27 Yan, L. L.; Zhang, Y.; Xu, B.; Tian, W. J. Fluorescent nanoparticles based on AIE fluorogens for bioimaging. Nanoscale2016, 8, 2471-2487.
28 Zhang, Y.; Chen, Y. J.; Li, X.; Zhang, J. B.; Chen, J. L.; Xu, B.;Fu, X. Q.; Tian, W. J. Folic acid-functionalized AIE Pdots based on amphiphilic PCL-b-PEG for targeted cell imaging.Polym. Chem. 2014, 5, 3824-3830.
29 Zhang, X. Q.; Zhang, X. Y.; Wang, S. Q.; Liu, M. Y.; Tao, L.;Wei, Y. Surfactant modification of aggregation-induced emission material as biocompatible nanoparticles:Facile preparation and cell imaging. Nanoscale 2013, 5, 147-150.
30 Qin,W.; Ding,D.; Liu,J. Z.; Yuan,W. Z.; Hu,Y.; Liu,B.;Tang, B. Z. Biocompatible nanoparticles with aggregation-induced emission characteristics as far-red/near-infrared fluorescent bioprobes for in vitro and in vivo imaging applications.Adv. Funct. Mater. 2012, 22, 771-779.
31 Geng, J. L.; Li, K.; Ding,D.; Zhang, X. H.; Qin,W.; Liu, J. Z.;Tang, B. Z.; Liu, B. Lipid-PEG-folate encapsulated nanoparticles with aggregation induced emission characteristics:Cellular uptake mechanism and two-photon fluorescence ima-ging. Small 2012, 8, 3655-3663.
32 Geng, J. L.; Li, K.; Pu, K. Y.; Ding, D.; Liu, B. Conjugated polymer and gold nanoparticle co-loaded PLGA nanocomposites with eccentric internal nanostructure for dual-modal targeted cellular imaging. Small 2013, 9, 2012-2019.
33 Li, K.; Qin, W.; Ding,D.; Tomczak,N.; Geng, J. L.; Liu,R. R.;Liu, J. Z.; Zhang, X. H.; Liu, H. W.; Liu, B.; Tang, B. Z. Photostable fluorescent organic dots with aggregation-induced emission(AIE dots)for noninvasive long-term cell tracing. Sci.Rep. 2013, 3, 1150.
34 Wang, Z. L.; Yan, L. L.; Zhang, L.; Chen, Y. J.; Li, H.; Zhang,J. B.; Zhang,Y.; Li,X.; Xu,B.; Fu,X. Q.; Sun,Z. C.; Tian,W.J. Ultra bright red AIE dots for cytoplasm and nuclear imaging.Polym. Chem. 2014, 5, 7013-7020.
35 Zhang, Y.; Chang, K. W.; Xu, B.; Chen, J. L.; Yan, L. L.; Ma,S. Q.; Wu, C. F.; Tian, W. J. Highly efficient near-infrared organic dots based on novel AEE fluorogen for specific cancer cell imaging. RSCAdv. 2015, 5, 36837-36844.
36 Wang, L.; Tan, W. H. Multicolor FRET silica nanoparticles by single wavelength excitation. Nano Lett. 2006, 6, 84-88.
37 Zhang, J.; Lakowicz, J. R. A model for DNA detection by metal-enhanced fluorescence from immobilized silver nanoparticles on solid substrate. J. Phys. Chem. B 2006, 110,2387-2392.
38 Jin, Y. H.; Ye, F. M.; Zeigler, M.; Wu, C. F.; Chiu, D. T. Nearinfrared fluorescent dye-doped semiconducting polymer dots.ACS Nano 2011, 5, 1468-1475.
39 Chung, C. Y. S.; Yam, V. W. W. Selective label-free detection of G-quadruplex structure of human telomere by emission spectral changes in visible-and-NIR region under physiological condition through the FRET of a two-component PPE-SO3-Pt(II)complex ensemble with Pt…Pt, electrostatic andπ-πinteractions. Chem. Sci. 2013, 4, 377-387.
40 Zhang,X. J.; Yu,J. B.; Rong,Y.; Ye,F. M.; Chiu,D. T.;Uvdal, K. High-intensity near-IR fluorescence in semiconducting polymer dots achieved by cascade FRET strategy. Chem.Sci. 2013, 4,2143-2151.
41 Wagh, A.; Qian, S. Y.; Law, B. Development of biocompatible polymeric nanoparticles for in vivo NIR and FRET imaging.Bioconjugate Chem. 2012, 23, 981-992.
42 Geng,J. L.; Zhu,Z. S.; Qin,W.; Ma,L.; Hu, Y.; Gurzadyan,G.G.; Tang, B. Z.; Liu, B. Near-infrared fluorescence amplified organic nanoparticles with aggregation-induced emission characteristics for in vivo imaging. Nanoscale 2014, 6, 939-945.
43 Xie,Z. Q.; Yang,B.; Xie,W. J.; Liu,L. L.; Shen,F. Z.; Wang,H. A.; Yang, X. Y.; Wang, Z. M.; Li, Y. P.; Hanif, M.; Yang,G. D.; Ye, L.; Ma, Y. G. A class of nonplanar conjugated compounds with aggregation-induced emission, structural and optical properties of 2,5-diphenyl-1,4-distyrylbenzene derivatives with all cis double bonds. J. Phys. Chem. B 2006, 110,20993-21000.
44 Hong, G. S.; Zou, Y. P.; Antaris, A. L.; Diao, S.; Wu, D.;Cheng, K.; Zhang, X. D.; Chen, C. X.; Liu, B.; He, Y. H.; Wu,J. Z.; Yuan, J.; Zhang, B.; Tao, Z. M.; Fukunaga, C.; Dai, H. J.Ultrafast fluorescence imaging in vivo with conjugated polymer fluorophores in the second near-infrared window. Nat.Commun. 2014, 5, 4206.
45 Rust, M. J.; Bates, M.; Zhuang, X. Sub-diffraction-limit imaging by stochastic optical reconstruction microscopy(STORM). Nat. Methods 2006, 3, 793-795.
46 Betzig,E.; Patterson,G. H.; Sougrat, R.; Lindwasser,O. W.;Olenych, S.; Bonifacino, J. S.; Davidson, M. W.; LippincottSchwartz, J.; Hess, H. F. Imaging intracellular fluorescent proteins at nanometer resolution. Science 2006, 313, 1642-1645.
47 Axelrod, D. Total internal reflection fluorescence microscopy in cell biology. Traffic 2001, 2, 764-774.
48 Chen,B.;Feng,G.X.;He,B.R.;Goh,C.;Xu,S.D.;RamosOrtiz, G.; Aparicio-Ixta, L.; Zhou, J.; Ng, L. G.; Zhao, Z. J.;Liu, B.; Tang, B. Z. Silole-based red fluorescent organic dots for bright two-photon fluorescence in vitro cell and in vivo blood vessel imaging. Small 2016, 12, 782-792.
49 Lou, X. D.; Zhao, Z. J.; Tang, B. Z. Organic dots based on AIEgens for two-photon fluorescence bioimaging. Small 2016,72, 6430-6450.
50 Zhen, S. J.; Wang, S. W.; Li, S. W.; Luo, W. W.; Gao, M.; Ng,L. G.; Goh, C. C.; Qin, A. J.; Zhao, Z. J.; Liu, B.; Tang, B. Z.Efficient red/near-infrared fluorophores based on benzo[1,2-b:4,5-b']dithiophene 1,1,5,5-tetraoxide for targeted photodynamic therapy and in vivo two-photon fluorescence bioimaging.Adv. Funct. Mater. 2018, 28. 1706945.
51 Shen, X. Y.; Yuan, W. Z.; Liu, Y.; Zhao, Q. L.; Lu, P.; Ma, Y.G.; Williams, I. D.; Qin, A. J.; Sun, J. Z.; Tang, B. Z. Fumaronitrile-based fluorogen, red to near-infrared fluorescence, aggregation-induced emission, solvatochromism, and twisted intramolecular charge transfer. J. Phys. Chem. C 2012, 116,10541-10547.
52 Liu, W.; Wang, Y. L; Han, X.; Lu, P.; Zhu, L.; Sun, C. W.; Qian, J.; He, S. L. Fluorescence resonance energy transfer(FRET)based nanoparticles composed of AIE luminogens and NIR dyes with enhanced three-photon near-infrared emission for in vivo brain angiography.. Nanoscale 2018, 10, 10025-10032.
53 Wang, Y.; Hu,R.; Xi,W.; Cai,F.; Wang, S.; Zhu,Z.; Bai,R.;Qian, J. Red emissive AIE nanodots with high two-photon absorption efficiency at 1040 nm for deep-tissue in vivo imaging.Biomed. Opt. Express 2015, 6, 3783-3794.
54 Alifu,N.; Yan,L. L.; Zhang,H. Q.; Zebibula,A.; Zhu,Z. G.;Xi, W.; Roe, A. W.; Xu, B.; Tian, W. J.; Qian, J. Organic dye doped nanoparticles with NIR emission and biocompatibility for ultra-deep in vivo two-photon microscopy under 1040 nm femtosecond excitation. Dyes Pigments 2017, 143, 76-85.
55Han,X.;Bai,Q.;Yao,L.;Liu,H.C.;Gao,Y.;Li,J.Y.;Liu,L.Q.; Liu, Y. L.; Li,X. X.; Lu,P.; Yang, B. Highly efficient solid-state near-infrared emitting material based on triphenylamine and diphenylfumaronitrile with an EQE of 2.58%in nondoped organic light-emitting diode. Adv. Funt. Mater. 2015,25, 7521-7529.
56 Zhu, Z. F.; Qian, J.; Zhao, X. Y.; Qin, W.; Hu, R. R.; Zhang, H.Q.; Li, D. Y.; Xu, Z. P.; Tang, B. Z.; He, S. L. Stable and sizetunable aggregation-induced emission nanoparticles encapsulated with nanographene oxide and applications in three-photon fluorescence bioimaging. ACS Nano 2016, 10. 588-597.
57 Lakowicz,J. R. in Principles of fluorescence spectroscopy,Springer, Berlin,3rd ed.,2006.
58 Polavarapu, L.; Manna, M.; Xu, Q. H. Biocompatible glutathione capped gold clusters as one-and two-photon excitation fluorescence contrast agents for live cells imaging. Nanoscale2011,3, 429-434.