Three-dimensional graphene nanosheet doped with gold nanoparticles as electrochemical DNA biosensor for bacterial detection

By Chen, Shiqiang; Cheng, Y. Frank; Voordouw, Gerrit
Published in Sensors and Actuators B: Chemical 2018

Abstract

Corrosion induced by sulfate-reducing bacteria (SRB) occurs in a wide variety of industry sectors. It is urgent to develop effective techniques for convenient detection of SRB in service environments and early diagnosis of the potential of microbial corrosion. Herein, a novel electrochemical DNA biosensor based on 3-dimensional graphene (3D G) hierarchical structure functionalized with Au nanoparticles (Au NPs) is developed, enabling detection of the dissimilatory sulfite reductase (DsrAB) gene from SRB with a good sensitivity and reliability, and proper selectivity. Various surface analysis techniques are used to characterize the morphology and composition of the 3D G-Au NP nanocomposite, and cyclic voltammetry is used to measure the electrochemical response of the nanocomposite biosensor to hybridization of a target DNA (TD). The improved performance of the developed biosensor is attributed to the large surface/volume ratio and good conductivity of the 3D G-Au NP hierarchical structure. Under optimized conditions, the biosensor shows a high sensitivity, with the detection limit up to 9.41

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