Nanoparticle-enhanced electrochemical biosensor with {DNA} immobilization and hybridization of Trichoderma harzianum gene

摘要

Abstract The genus Trichoderma is a soil-borne fungi which in numerous reports has been successfully used as a biological control agent against various plant pathogens. The identification of Trichoderma species worldwide is currently deduced from micro-morphological descriptions which are tedious and prone to error. Electrochemical approaches are currently being developed for the detection and analysis of DNA. In the present study, an electrochemical {DNA} biosensor was successfully developed based on ionic liquid (e.g., 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][Otf])), ZnO nanoparticles and a chitosan (CHIT) nanocomposite membrane on a modified gold electrode (AuE). A single-stranded {DNA} probe was immobilized on this electrode. Methylene blue (MB) was used as the hybridization indicator to monitor the hybridization reaction of the target DNA. Under optimal conditions using differential pulse voltammetry (DPV), the target {DNA} sequences were detectable at concentration ranges of 1.0 × 10?18–1.82 × 10?4 mol L?1, and the detectable limit was 1.0 × 10?19 mol L?1. The developed {DNA} biosensor enables the study of hybridization with crude {DNA} fragments and the results of this study confirm that this {DNA} biosensor provides a fast, sensitive and convenient way for the species level identification of Trichoderma harzianum.