Electrochemical immunoassay for gastric cancer biomarker pepsinogen I detection based on PdAgPt/MoS2

This study presents a novel electrochemical immunosensor for the detection of pepsinogen I, a potential biomarker for gastric cancer, based on a PdAgPt/MoS2 nanocomposite. The nanocomposite was synthesized and characterized, demonstrating enhanced electron transfer properties and a large electroactive surface area. The optimized immunosensor exhibited a wide linear range of 0.5-200 ng/mL and a low detection limit of 0.167 ng/mL. The sensor showed excellent selectivity, with interfering substances exhibiting relative responses below 5%. Reproducibility tests yielded a relative standard deviation of 3.8%, and the sensor retained 95.6% of its initial response after 30 days of storage. Analysis of spiked serum samples resulted in recoveries ranging from 96.8% to 104.5%, demonstrating the sensor's potential for clinical applications in early gastric cancer detection.