Solution-phase, dual LSPR-SERS plasmonic sensors of high sensitivity and stability based on chitosan-coated anisotropic silver nanoparticles
Solution-phase, dual LSPR-SERS plasmonic sensors of high sensitivity and stability based on chitosan-coated anisotropic silver nanoparticles
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DOI：
10.1039/c0jm03329d
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发表时间：
2011-01-01
影响因子：
--
通讯作者：
Astilean, Simion
中科院分区：
文献类型：
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作者：
Potara, Monica;Gabudean, Ana-Maria;Astilean, Simion
需要设计高度灵敏的等离子体传感器，其赋予良好的生物相容性和光学稳定性以检测生物介质中的低水平分析物。在这项研究中，我们报告的形成壳聚糖包裹的银纳米粒子的三角形形状的溶液中的协同作用的壳聚糖和柠檬酸三钠的存在下，银种子和抗坏血酸。已经揭示，这些各向异性的银纳米粒子包埋在生物聚合物壳是特别稳定的，可以成功地用作多功能的等离子体基片的分子传感溶液中。特别是，结合的探针分子单层（对氨基苯硫酚，p-ATP）在单个壳聚糖涂层的银纳米粒子的表面被证明都通过局部表面等离子体共振（LSPR）位移和表面增强的拉曼散射（Sers）光谱。虽然LSPR位移测定可用于信号分子结合事件，但Sers允许识别探针分子并阐明其在金属表面上的取向。生物传感应用的概念验证和等离子体平台的双重功能通过组合LSPR-SERS检测重要的生物分子腺嘌呤进行评估。壳聚糖-银纳米结构通过整合Sers测量来扩展LSPR传感的标准方法并作为双等离子体传感器操作的潜力对于生物流体中的分析物的调查将是非常有吸引力的。
There is a need to design highly sensitive plasmonic sensors which impart a good biocompatibility and optical stability to detect low levels of analytes in biological media. In this study we report the formation of chitosan-coated silver nanoparticles of triangular shape in solution by synergistic action of chitosan and trisodium citrate in the presence of silver seeds and ascorbic acid. It has been revealed that these anisotropic silver nanoparticles entrapped in biopolymeric shells are particularly stable and can be successfully used as versatile plasmonic substrates for molecular sensing in solution. In particular, the binding of the probe molecule monolayer (para-aminothiophenol, p-ATP) at the surface of individual chitosan-coated silver nanoparticles was demonstrated both by localized surface plasmon resonance (LSPR) shifts and surface-enhanced Raman scattering (SERS) spectra. While the LSPR-shift assay is operational for signaling molecular binding events, the SERS allows identifying the probe molecules and elucidating its orientation on the metal surface. The proof of concept for biosensing applications and dual functionality of plasmonic platform are evaluated through the combined LSPR-SERS detection of significant biological molecules, adenine. The potential of chitosan-silver nanostructures to extend the standard approach of LSPR sensing by integrating SERS measurements and operate as dual plasmonic sensors would be very attractive for investigation of analytes in biological fluids.