Nano-ZnO/Chitosan Composite Film Modified Electrode for Voltammetric Detection of DNA Hybridization

Abstract

A sensitive electrochemical DNA biosensor based on nano-ZnO/chitosan composite matrix for DNA hybridization detection was developed. The Nano-ZnO was synthesized by the hydrothermal method and dispersed in chitosan, which was used to fabricate the modification of the glassy carbon electrode (GCE) surface. The ZnO/chitosan-modified electrode exhibited good biocompatibility and excellent electrochemical conductivity. The hybridization detection was monitored with differential pulse voltammetry (DPV) measurement using methylene blue (MB) as an indicator. The established biosensor can effectively discriminate complementary target sequence and two-base-mismatched sequence, with a detection limit of 1.09 × 10⁻¹¹ mol L⁻¹ of complementary target.

Keywords:

• Chitosan
• DNA biosensor
• Methylene blue
• ZnO

The authors are grateful for the financial support provided by the National Natural Science Foundation of China (No. 20435010) and Henan University of Technology (No. 150196).