An electrochemical DNA biosensor based on nitrogen-doped graphene nanosheets decorated with gold nanoparticles for genetically modified maize detection.

Abstract

Areliable electrochemical biosensor is reportedbased on nitrogen-doped graphene nanosheets and gold nanoparticle (Au/N-G) nanocomposites for the event-specific detection of GM maize MIR162. The differential pulse voltammetry response of methylene blue (MB) was chosen to monitor the target DNA hybridization event. Under the optimum conditions, the peak current increased linearly with the logarithm of the concentration of DNA in the range 1.0 × 10-14 to 1.0 × 10-8M, and the detection limit was 2.52 × 10-15M (S/N = 3). It isalso demonstrated that the DNA biosensor has high selectivity, good stability, and fabrication reproducibility. Thebiosensor has beeneffectively applied to detect MIR162 in real samples, showing its potential as an effective tool for GM crop analysis. These results will contribute to the development of new portable transgenic detection systems. Graphical abstract .