Oxygen Vacancy Modulated MnO2 Bi-Electrode System for Attomole-Level Pathogen Nucleic Acid Sequence Detection

DNA amplification detection is typically a lengthy and sophisticated procedure involving high-end instrumentation. Electrochemical detection has recently opened a relatively low budget, a straightforward and speedy method for detection with the aid of an electrochemically active redox probe. However, electrochemical sensors of nucleic acid amplification characteristically employ a tri-electrode geometry involving standard reference electrode usually made up of a noble metal that adds up the cost of detection. This work proposes a sensitive and rapid approach for detecting the endpoint of nucleic acid amplification test using a novel bi-electrode sensing geometry. The sensing layer of the electrode was comprised of a transition metal oxide to tune its electronic state for regulating its electrochemical response. The fabricated device was then used to detect dengue virus sequence DNA (using rolling circle amplification) and Staphylococcus aureus genomic DNA (using polymerase chain reaction) with the limit of detection in the order of 103 target DNA copies.