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Updated: Apr 19, 2026
Bacterial Detection & Identification Using Electrochemical Sensors
Published on: April 23, 2013
An electrochemical biosensor for sensitive detection of microRNA-155: combining target recycling with cascade
Xiaoyan Wu1, Yaqin Chai, Pu Zhang
1Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, P. R. China.
Abstract:
In this work, a new electrochemical biosensor based on catalyzed hairpin assembly target recycling and cascade electrocatalysis (cytochrome c (Cyt c) and alcohol oxidase (AOx)) for signal amplification was constructed for highly sensitive detection of microRNA (miRNA). It is worth pointing out that target recycling was achieved only based on strand displacement process without the help of nuclease. Moreover, porous TiO2 nanosphere was synthesized, which could offer more surface area for Pt nanoparticles (PtNPs) enwrapping and enhance the amount of immobilized DNA strand 1 (S1) and Cyt c accordingly. With the mimicking sandwich-type reaction, the cascade catalysis amplification strategy was carried out by AOx catalyzing ethanol to acetaldehyde with the concomitant formation of high concentration of H2O2, which was further electrocatalyzed by PtNPs and Cyt c. This newly designed biosensor provided a sensitive detection of miRNA-155 from 0.8 fM to 1 nM with a relatively low detection limit of 0.35 fM.
