An ingenious designed dual mode self-powered biosensing platform based on graphdiyne heterostructure substrate for instant hepatocarcinoma marker detection

We report here for the first time a self-powered biosensing platform based on graphene/graphdiyne/graphene (GDY-Gr) heterostructure substrate material for ultrasensitive hepatocarcinoma marker (microRNA-21) detection in both electrochemical and colorimetric test modes. The dual-mode signal intuitively displayed on a smartphone fundamentally improves the detection accuracy. In electrochemical mode, the calibration curve is established in the linear range of 0.1–10000 fM, and the detection limit is as low as 0.333 fM (S/N = 3). Simultaneously, colorimetric analysis of the miRNA-21 is realized by using ABTS as an indicator. The detection limit is confirmed as 32 fM (S/N = 3), and miRNA-21 of concentration from 0.1 pM to 1 nM exhibit a linear relationship with R2 = 0.9968. Overall, the combination of GDY-Gr and multiple signal amplification strategy significantly improved the sensitivity by 310 times compared with traditional enzymatic biofuel cells (EBFCs) based detection platform, showing broad application prospects for on-site analysis and future mobile medical services.