Novel Self-Powered Biosensor Based on Highly Efficient Cosignal Accelerator and Multiple Signal Amplification Strategies toward Ultrasensitive miRNA-141 Assay.

A highly sensitive self-powered biosensor is designed based on gold-platinum nanorods (AuPt NRs) and the cascade reaction of catalytic hairpin assembly (CHA) and hybrid chain reaction (HCR) toward the miRNA-141 assay. As a cosignal accelerator, AuPt NRs enhance electrical conductivity between glucose oxidase (GOD) and a carbon paper (CP) electrode, thereby assisting in output signal enhancement. The cascade reaction of CHA-HCR is employed to efficiently amplify the detection signal and improve the sensitivity of the self-powered biosensor. Consequently, the self-powered biosensor provides highly sensitive detection of miRNA-141 with a wide linear response in the range of 0.1-104 fM and exhibits a low limit of detection (LOD) of 0.034 fM (S/N = 3). In addition, the self-powered biosensor exhibits high applicability in a real sample for the miRNA-141 assay.