负载银簇的硅基杂化纳米颗粒制备及其SERS性能

Silver Clusters-loaded Silica-based Hybrid Nanoparticles:Synthesis and SERS Performance

本研究发展了一种简便的“原位还原”策略构建负载银簇的硅基杂化纳米颗粒(Ag@SHNPs)。首先利用两亲性嵌段共聚物PS_(89)-b-PAA_(16)自组装行为和3-巯基丙基三甲氧基硅烷(MPTMS)在亲水链段PAA区域的水解缩聚反应形成有机硅胶束杂化纳米结构,再利用有机硅骨架中丰富的巯基作为还原位点,原位将银盐转化为银簇,最终得到负载银簇的硅基杂化纳米颗粒,并对该杂化纳米颗粒的形貌、结构以及成分组成作了分析。通过测试材料对不同细胞系的毒性验证了其良好的生物相容性。最后以4-巯基苯甲酸(4-MBA)为探针分子,对硅基杂化颗粒基底的表面增强拉曼散射(SERS)活性进行检测。在532 nm波长的激光激发下,4-MBA标记的硅基杂化纳米颗粒展示出明显的拉曼信号增强特性,增强因子约为10^(5)。因此,该硅基杂化基底材料在SERS生物成像和高灵敏检测方面具有潜在的应用前景。

In this research,a facile“in-situ reduction”strategy was developed to construct silver clusters-loaded silica-based hybrid nanoparticles(Ag@SHNPs).Firstly,the formation of organosilica-micellar hybrid nanostructure was achieved by self-assembly of amphiphilic block copolymer PS_(89)-b-PAA_(16) and hydrolysis,and polycondensation of(3-mercaptopropyl)trimethoxysilane(MPTMS)on the hydrophilic PAA segment.Then,the abundant thiol groups in the organosilica framework were used as reduction sites to in-situ convert the silver salt into silver clusters,and finally the Ag@SHNPs were obtained.Morphology,structure and composition of the hybrid nanoparticles were analyzed,and their cytotoxicity on different cell lines were explored,showing good biocompatibility.The surface enhanced Raman scattering(SERS)activity of the Ag@SHNPs substrate were detected by using 4-mercaptobenzoic acid(4-MBA)as the probe molecule.Under an excitation wavelength of 532 nm laser,4-MBA-labeled Ag@SHNPs exhibited obvious Raman enhanced signal with an enhancement factor of about 10^(5).Therefore,the silica-based hybrid substrate material shows potential application prospects in SERS bioimaging and high-sensitivity detection.