This paper describes improved sensitivity when using biosensors based on microfabricated microelectrodes to detect DNA, with the goal of progressing towards a low cost and mass manufacturable assay for antibiotic resistance in tuberculosis (TB). The microelectrodes gave an improvement in sensitivity compared to polycrystalline macroelectrodes. In addition, experimental parameters such as redox mediator concentration and experimental technique were investigated and optimised. It was found that lower concentrations of redox mediator gave higher signal changes when measuring hybridisation events and, at these lower concentrations, square wave voltammetry was more sensitive and consistent than differential pulse voltammetry. Together, this paper presents a quantifiable comparison of macroelectrode and microelectrode DNA biosensors. The final assay demonstrates enhanced sensitivity through reduction of sensor size, reduction of redox mediator concentration and judicious choice of detection technique, therefore maintaining manufacturability for incorporation into point of care tests and lab-on-a-chip devices.

本文描述了使用基于微制造的微电极的生物传感器检测DNA时提高的灵敏度，目的是朝着低成本，可大规模生产的结核病（TB）抗生素耐药性检测方法发展。与多晶大电极相比，微电极的灵敏度有所提高。此外，还研究和优化了氧化还原介体浓度和实验技术等实验参数。发现在测量杂交事件时，较低浓度的氧化还原介体会产生较高的信号变化，并且在这些较低浓度下，方波伏安法比差分脉冲伏安法更灵敏且一致。总之，本文提出了大电极和微电极DNA生物传感器的定量比较。