Issue 54, 2015

A novel colorimetric triple-helix molecular switch aptasensor based on peroxidase-like activity of gold nanoparticles for ultrasensitive detection of lead(ii)

Abstract

Lead (Pb) is a serious environmental contaminant and one of the most toxic heavy metals. In this study a colorimetric aptasensor was designed for selective, sensitive and rapid detection of Pb2+, based on a triple-helix molecular switch (THMS) and peroxidase-like activity of gold nanoparticles (AuNPs). This sensor inherits the properties of THMS, including high stability and preserving the affinity and selectivity of the original aptamer and properties of peroxidase-like activity of AuNPs, such as fast readout and improvement of the sensitivity. In the absence of Pb2+, THMS is intact, leading to complete peroxidase-like activity of AuNPs and an obvious color change to purplish-blue. In the presence of Pb2+, the aptamer binds to Pb2+, the signal transduction probe (STP) leaves the THMS and adsorbs onto the surface of AuNPs, leading to inhibition of the peroxidase-like activity of AuNPs and no color change is observed. The designed aptasensor showed high selectivity toward Pb2+ with a limit of detection as low as 602 pM for Pb2+. The presented aptasensor was successfully used to detect Pb2+ in water and serum.

Graphical abstract: A novel colorimetric triple-helix molecular switch aptasensor based on peroxidase-like activity of gold nanoparticles for ultrasensitive detection of lead(ii)

Article information

Article type
Paper
Submitted
09 Apr 2015
Accepted
08 May 2015
First published
08 May 2015

RSC Adv., 2015,5, 43508-43514

A novel colorimetric triple-helix molecular switch aptasensor based on peroxidase-like activity of gold nanoparticles for ultrasensitive detection of lead(II)

S. M. Taghdisi, N. M. Danesh, P. Lavaee, A. S. Emrani, M. Ramezani and K. Abnous, RSC Adv., 2015, 5, 43508 DOI: 10.1039/C5RA06326D

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