A displacement principle for mercury detection by optical waveguide and surface enhanced Raman spectroscopy

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• 作者：Yongmei Ma ; Honglin Liu ; Kai Qian ; Liangbao Yang ; Jinhuai Liu
• 关键词：Displacement ; Nanoparticle ; Mercury ; Optical waveguide ; Surface enhanced Raman spectroscopy
• 刊名：Journal of Colloid and Interface Science
• 出版年：2012
• 出版时间：15 November, 2012
• 年：2012
• 卷：386
• 期：1
• 页码：451-455
• 全文大小：957 K

文摘

A novel displacement principle of metal nanoparticles for target analysis, differing from the usual target-induced aggregation principle, was proved feasible by the use of para-aminothiophenol coupled Au nanoparticles (PATP-Au) multilayer as probes to detect Hg²⁺. The PATP-Au multilayer was fabricated through layer-by-layer assembly of Au nanoparticles on optical waveguide (OWG) chip surface using para-aminothiophenol (PATP) as coupling molecules. The localized surface plasmon resonance (LSPR) extinction from Au nanoparticles and the PATP as a Raman reporter enable to easily capture changes in PATP-Au multilayer by OWG and of surface enhanced Raman spectroscopy, respectively. The introduction of the Hg²⁺, which has a higher binding affinity to the thiol group of PATP, greatly destroyed the multilayer structure, and produced a large change, several folds higher than the noise, in LSPR features and Raman signals of PATP-Au multilayer probes, and resulted in an excellent selectivity for Hg²⁺ detection at a low level of 1 nM. This investigation provides us more ideas on the future development of surface analysis techniques for the detection of various target analytes.