A Multiple Signal Amplification Strategy from the Cascade Reactions of Catalytic Hairpin Assembly and Hybridization Chain Reaction for a Novel Bioelectronic Sensor

A highly sensitive bioelectronic sensor (BES) was developed to analyze miRNA-182, utilizing Ag@Au hexagonal nanoplates (Ag@Au HNPs) in conjunction with catalytic hairpin assembly (CHA) and hybridization chain reaction (HCR) cascade reactions. The Ag@Au HNPs improve the conductivity between glucose oxidase (GOD) and carbon paper (CP), thereby contributing to enhanced electron transport in the BES. In addition, the multi-amplification strategy of the BES integrates the CHA-HCR cascade reaction with a capacitor to efficiently amplify the detection signal and enhance the sensitivity. As a result, the BES enables highly sensitive detection of miRNA-182 with a low limit of detection (LOD) of 0.34 fM (S/N = 3) in a wide linear response range of 1∼104 fM. Furthermore, the BES exhibited significant applicability in the detection of miRNA-182 in real samples.