Ultrasensitive electrochemical biosensing platform based on spherical silicon dioxide/molybdenum selenide nanohybrids and triggered Hybridization Chain Reaction.

An ultrasensitive sandwich-type electrochemical biosensor for DNA detection is developed based on spherical silicon dioxide/molybdenum selenide (SiO2@MoSe2) and graphene oxide-gold nanoparticles (GO-AuNPs) hybrids as carrier triggered Hybridization Chain Reaction (HCR) coupling with multi-signal amplification. The proposed sensoring assay utilizes a spherical SiO2@MoSe2/AuNPs as sensing platform and GO-AuNPs hybrids as carriers to supply vast binding sites. H2O2+HQ system is used for DNA detection and HCR as the signal and selectivity enhancer. The sensor is designed in sandwich type to increase the specificity. As a result, the present biosensor exhibits a good dynamic range from 0.1fM to 100pM with a low detection limit of 0.068fM (S/N=3). This work shows a considerable potential for quantitative detection of DNA in early clinical diagnostics.