Aggregation of Individual Sensing Units for Signal Accumulation: Conversion of Liquid-Phase Colorimetric Assay into Enhanced Surface-Tethered Electrochemical Analysis

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• 作者：Tianxiang Wei ; Tingting Dong ; Zhaoyin Wang ; Jianchun Bao ; Wenwen Tu ; Zhihui Dai
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：July 22, 2015
• 年：2015
• 卷：137
• 期：28
• 页码：8880-8883
• 全文大小：341K
• ISSN：1520-5126

文摘

A novel concept is proposed for converting liquid-phase colorimetric assay into enhanced surface-tethered electrochemical analysis, which is based on the analyte-induced formation of a network architecture of metal nanoparticles (MNs). In a proof-of-concept trial, thymine-functionalized silver nanoparticle (Ag-T) is designed as the sensing unit for Hg²⁺ determination. Through a specific T-Hg²⁺-T coordination, the validation system based on functionalized sensing units not only can perform well in a colorimetric Hg²⁺ assay, but also can be developed into a more sensitive and stable electrochemical Hg²⁺ sensor. In electrochemical analysis, the simple principle of analyte-induced aggregation of MNs can be used as a dual signal amplification strategy for significantly improving the detection sensitivity. More importantly, those numerous and diverse colorimetric assays that rely on the target-induced aggregation of MNs can be augmented to satisfy the ambitious demands of sensitive analysis by converting them into electrochemical assays via this approach.