Biologically modified microelectrode sensors provide enhanced sensitivity for detection of nucleic acid sequences from Mycobacterium tuberculosis

Ewen O. Blair, Stuart Hannah, Vincent Vezza, Hüseyin Avci, Tanil Kocagoz, Paul A. Hoskisson, Fatma D. Güzel, Damion K. Corrigan

Research output: Contribution to journalArticle


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 a near 20 times 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.
Original languageEnglish
Article number100008
Number of pages9
JournalSensors and Actuators Reports
Issue number1
Early online date25 Apr 2020
Publication statusE-pub ahead of print - 25 Apr 2020



  • biosensor
  • microelectrodes
  • DNA sensor
  • tuberculosis
  • microfabrication

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