Construction of an Integrated Device of a Self-Powered Biosensor and Matching Capacitor Based on Graphdiyne and Multiple Signal Amplification: Ultrasensitive Method for MicroRNA Detection.

The detection of microRNA (miRNA) in human serum has great significance for cancer prevention. Herein, a novel self-powered biosensing platform is developed, which effectively integrates an enzymatic biofuel cell (EBFC)-based self-powered biosensor with a matching capacitor for miRNA detection. A catalytic hairpin assembly and hybrid chain reaction are used to improve the analytical performance of EBFC. Furthermore, the matching capacitor is selected as an auxiliary signal amplifying device, and graphdiyne is applied as substrate material for EBFC. The results confirm that the developed method obviously increases the output current of EBFC, and the sensitivity can reach 2.75 μA/pM, which is 786% of pure EBFC. MiRNA can be detected in an expanded linear range of 0.1-100000 fM with a detection limit of 0.034 fM (S/N = 3). It can offer a selective and sensitive platform for nucleotide sequence detection with great potential in clinical diagnostics.