1：Experimental Design and Method Selection:

The study designed a PEC biosensor using energy transfer between CQDs and AuNPs, with Mo2C nanotubes as nanocarriers to enhance conductivity. DSN-assisted signal amplification was employed for sensitivity.

2：Sample Selection and Data Sources:

Synthetic miRNAs (miRNA-159b and miRNA-166a) and DNA probes were used, sourced from Takara Biotechnology and Sangon Biotech.

3：List of Experimental Equipment and Materials:

Equipment included TEM (Tecnai G2 F20), SEM (Quanta Q400), UV-vis spectrophotometer (Shimadzu UV-3600), fluorescence spectrophotometer (Cary Eclipse), PEC system with Xe lamp, electrochemical workstations (CHI832A, CHI660C). Materials included DSN, MPA, TCEP, Tris, EDC, NHS, HAuCl4, and various buffers.

4：Experimental Procedures and Operational Workflow:

Synthesis of CQDs@Mo2C, preparation of AuNPs and labeled probes, fabrication of the biosensor on ITO electrodes, hybridization and DSN cleavage steps, and PEC measurements under visible light at -0.3 V applied potential.

5：3 V applied potential. Data Analysis Methods:

5. Data Analysis Methods: Photocurrent responses were measured and analyzed for linearity and detection limits using standard deviation from triplicate measurements.