1：Experimental Design and Method Selection:

The study involved designing DNA sequences (ssDNA and hairpin DNA) to template AgNCs, exploring the effect of various metal ions on fluorescence enhancement, and applying this to detect telomerase activity using a molecular beacon (MB) system. Theoretical models include the role of DNA secondary structures and metal ion interactions.

2：Sample Selection and Data Sources:

DNA sequences were synthesized with varying cytosine content and structures. Telomerase standards and cell extracts (e.g., HepG2, A549, HeLa, CCC-HPF-1, CCC-HEL-1) were used as sources for telomerase activity.

3：List of Experimental Equipment and Materials:

DNA oligonucleotides, AgNO3, NaBH4, phosphate buffers (PB1, PB2), ammonium acetate buffer, dNTPs, telomerase ELISA kit, UV-vis spectrometer (Shimadzu UV-2450), fluorescence spectrophotometer (Shimadzu FR-6000), fluorescence lifetime spectrometer (Edinburgh Instruments FLS980), CD spectrometer (Applied Photophysics Chirascan), TEM (JEOL 2100F).

4：Experimental Procedures and Operational Workflow:

DNA templates were mixed with buffer, heated, cooled, then AgNO3 and NaBH4 were added to synthesize AgNCs. For telomerase detection, MB was incubated with TP, telomerase, and dNTPs, followed by AgNCs synthesis and fluorescence measurement after specific times.

5：Data Analysis Methods:

Fluorescence intensity was measured and correlated with telomerase activity. Linear regression was used for calibration curves. Statistical analysis included detection limit calculation (3σ/k).