摘要
      在本研究中，通过将发夹DNA探针组装在沉积有金纳米颗粒的氧化铟锡（ITO）电极上，成功地制备了抗生素抗性基因（ARGs）检测生物传感器。比较了恒电位法、恒电流法和循环伏安法三种沉积方法，证明循环伏安法是最有效的沉积方法。其最佳电压范围为-0.9至-0.2V，循环40次，可以在ITO电极上沉积均匀致密的纳米金膜。此外，使用碱基错配的DNA来研究传感器的特异性。DPV的结果表明，只有当生物传感器与完全互补的DNA杂交时，电流才能显著降低到281.0μA。此外，ARGs的浓度与电化学信号之间存在很强的相关性。相关系数达到0.987，检测限为30.0 pg/μl，满足水环境中ARGs监测的要求。总之，本研究制备的生物传感器具有令人满意的特异性和灵敏度，有利于实际应用。
Abstract
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 voltammetric 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 mismatched bases was applied to study the specificity of the sensor. Results of DPV showed that the current significantly reduced to 281.0 μA 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/μl, 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.

https://www.sciencedirect.com/science/article/abs/pii/S0026265X22007810