A polyaniline-reduced graphene oxide nanocomposite as a redox nanoprobe in a voltammetric DNA biosensor for Mycobacterium tuberculosis

作者：Chen, Yuhan; Li, Youlun; Yang, Yang; Wu, Fangni; Cao, Jun; Bai, Lijuan^*

来源：Microchimica Acta, 2017, 184(6): 1801-1808.

DOI：10.1007/s00604-017-2184-5

• Sandwich DNA assay
• Tuberculosis diagnosis
• Electrochemical detection
• Redox nanocomposite
• Signal amplification

This article describes the construction of a sandwich-type of DNA biosensor for detecting a specific DNA sequence of Mycobacterium tuberculosis (MTB). A polyaniline-reduced graphene oxide (PANI-rGO) composite with favorable electrochemical activity was used as a redox nanoprobe for the generation of the voltammetric signal. The composite was decorated with gold nanoparticles (AuNPs) onto which the signal probe was immobilized to form the tracer label. After hybridization between target DNA and tracer label, the voltammetric signal resulting from the polyaniline-reduced graphene oxide (PANI-rGO) redox probe can be apparently observed. The biosensor can detect the specific IS6110 DNA sequence of MTB in the 0.1 pM to 10 nM concentration range, and the detection limit is as low as 50 fM (at an S/N ratio of 3). The biosensor is also highly specific and does not recognize mismatches. It was applied to the determination of denatured PCR products in clinical samples such as sputum, and the results agreed with those obtained by gel electrophoresis. This assay provides a versatile and powerful tool for detection of MTB, and probably for other pathogens if appropriate molecular markers are available.

• 出版日期2017-6
• 单位重庆医科大学