Preparation of an electrochemical biosensor based on indium tin oxide and its performance in detecting antibiotic resistance genes

In this study, an antibiotic resistance genes (ARGs) detection biosensor was successfully fabricated by assembling the hairpin DNA probe on an indium tin oxide (ITO) electrode deposited with gold nanoparticles. Three methods of potentiostatic, galvanostatic and cyclic voltammetric for deposition were compared, and the cyclic voltam -metric was proved to be the most effective one. The optimal voltage range for it was-0.9 to-0.2 V with 40 cycles, which can deposit uniform and dense nano-gold film on the ITO electrode. In addition, DNA with mis-matched bases was applied to study the specificity of the sensor. Results of DPV showed that the current significantly reduced to 281.0 mu A only when the biosensor was hybridized with completely complementary DNA. What's more, there was a strong correlation between the concentration of ARGs and electrochemical signal. The correlation coefficient reached 0.987, and the detection limit was 30.0 pg/mu l, which met the demand for monitoring ARGs in the water environment. All in all, the biosensor prepared in this study possesses satisfactory specificity and sensitivity, which is beneficial for practical application.

Automated summary

A biosensor for detecting antibiotic resistance genes (ARGs) was successfully prepared by assembling a hairpin DNA probe on an indium tin oxide (ITO) electrode deposited with gold nanoparticles. The cyclic voltammetric method was proven to be the most effective deposition method. The biosensor exhibited satisfactory specificity and sensitivity, showing strong correlation with the concentration of ARGs.