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A Method for Selecting Structure-switching Aptamers Applied to a Colorimetric Gold Nanoparticle Assay
Published on: February 28, 2015
An Ultrasensitive Biosensing Platform Employing Acetylcholinesterase and Gold Nanoparticles
1College of Chemistry, Research Center for Analytical Sciences, State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Molecular Recognition and Biosensing, and Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin, 300071, China. liudb@nankai.edu.cn.
Abstract:
Enzyme-linked immunosorbent assay (ELISA) is a well-known strategy for biomarker detection with a color change, which can be seen by the naked eyes. However, the moderate sensitivity of conventional ELISA limits its applications in many cases where the concentrations of biomarker are very low, such as cancer diagnosis. Here we describe an ultrasensitive colorimetric assay based on acetylcholinesterase (AChE)-catalyzed hydrolysis reaction, whose products trigger the aggregation of gold nanoparticles (AuNPs), causing a distinct color change of the solution from red to purple. This enhanced colorimetric immunoassay offers extremely high sensitivity and specificity. In this study, we employed enterovirus 71 (EV71), the major cause of hand, foot, and mouth disease (HFMD), as a model to evaluate the analytical performance of the plasmonic immunoassay.

