title: Coupling gold nanoparticles to silica nanoparticles through disulfide bonds for glutathione detection.
abstract: Advances in the controlled assembly of nanoscale building blocks have resulted in functional devices which can find applications in electronics, biomedical imaging, drug delivery etc. In this study, novel covalent nanohybrid materials based upon [Ru(bpy)3](2+)-doped silica nanoparticles (SiNPs) and gold nanoparticles (AuNPs), which could be conditioned as OFF-ON probes for glutathione (GSH) detection, were designed and assembled in sequence, with the disulfide bonds as the bridging elements. The structural and optical properties of the nanohybrid architectures were characterized using transmission electron microscopy, UV-vis spectroscopy and fluorescence spectroscopy, respectively. Zeta potential measurements, x-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were employed to monitor the reaction processes of the SiNPs-S-S-COOH and SiNPs-S-S-AuNPs synthesis. It was found that the covalent nanohybrid architectures were fluorescently dark (OFF state), indicating that SiNPs were effectively quenched by AuNPs. The fluorescence of the OFF-ON probe was resumed (ON state) when the bridge of the disulfide bond was cleaved by reducing reagents such as GSH. This work provides a new platform and strategy for GSH detection using covalent nanohybrid materials.
authors: Key Laboratory of Sensing Technology and Biomedical Instruments (Guangdong Province), School of Engineering, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors: Yupeng
authors: Y
authors: Shi
authors: Heng
authors: H
authors: Zhang
authors: Zhenfeng
authors: Z
authors: Yue
authors: Zhaomin
authors: Z
authors: Zhang
authors: Kar-Seng
authors: KS
authors: Teng
authors: Mei-Jin
authors: MJ
authors: Li
authors: Changqing
authors: C
authors: Yi
authors: Mengsu
authors: M
authors: Yang
mesh_terms: D004220:Disulfides / Q000737:chemistry*; D005978:Glutathione / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D053758:Nanoparticles / Q000648:ultrastructure; D056951:Photoelectron Spectroscopy; D012822:Silicon Dioxide / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D004220:Disulfides; D006046:Gold; D012822:Silicon Dioxide; D005978:Glutathione