Disposable CD electrodes for DNA-based detection of Ralstonia solanacearum

In this study, we describe a disposable electrode system on a polycarbonate substrate intended for DNA-based detection of the bacterial plant pathogen Ralstonia solanacearum. The electrode system was prepared by using a laser engraver to expose and isolate areas of gold film on gold compact discs to make working, auxiliary, and reference electrodes. Silver and silver chloride were subsequently coated onto the reference electrode by electrochemical treatment. The CD electrode system performed comparably to commercial screen-printed electrodes when used for analysis of ferricyanide by cyclic voltammetry, and also showed superior electrode surface smoothness. Current efforts are focused on coupling DNA hybridization probes to these electrode systems to detect loop-mediated isothermal amplification (LAMP) amplicons of R. solanacearum.