1：Experimental Design and Method Selection:

The study designed a colorimetric aptasensor using AgNPs and an unfunctionalized anti-AD aptamer. The principle relies on the dispersion of aggregated metal nanoparticles in high salt conditions due to aptamer-target binding, monitored via UV–vis absorption spectroscopy.

2：Sample Selection and Data Sources:

Adenosine solutions at various concentrations (60–280 nM) and urine samples from two lung cancer patients were used. Samples were diluted and filtered to remove interferences.

3：List of Experimental Equipment and Materials:

Equipment includes a PerkinElmer Lambda 25 UV–visible spectrophotometer, Philips EM 208S TEM, and various chemicals such as silver nitrate, sodium citrate, ascorbic acid, Tris-HCl buffer, NaCl, and the anti-AD aptamer from Macrogen.

4：Experimental Procedures and Operational Workflow:

AgNPs and AuNPs were synthesized using citrate reduction. For AD measurement, AD solution, aptamer, buffer, and nanoparticles were mixed, incubated, NaCl was added to induce aggregation, and absorbance was measured at specific wavelengths (A400/A520 for AgNPs, A520/A680 for AuNPs). Real samples were pretreated by centrifugation and filtration.

5：Data Analysis Methods:

Data were analyzed using calibration curves, limit of detection (LOD) calculated as 3Sb/m, relative standard deviation (RSD) for precision, and recovery tests for accuracy. Statistical comparisons used F-test and t-test.