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

Abstract This study presents a novel electrochemical immunosensor for the detection of pepsinogen I, a potential biomarker for gastric cancer, based on a unique PdAgPt/MoS₂ nanocomposite. The key innovation lies in the synergistic combination of trimetallic PdAgPt nanoparticles with MoS₂ nanoflowers, which has not been previously reported for pepsinogen I detection. This hybrid material demonstrates exceptional electron transfer properties and a significantly larger electroactive surface area compared to conventional materials. The optimized immunosensor exhibits superior performance metrics: a wide linear range of 0.5–200 ng ml⁻¹ and an unprecedented low detection limit of 0.173 ng ml⁻¹, surpassing existing detection methods. The sensor shows remarkable selectivity with interfering substances exhibiting relative responses below 5%, excellent reproducibility (RSD 3.8%), and outstanding stability (95.6% retention after 30 d). Analysis of spiked serum samples resulted in recoveries ranging from 96.8% to 104.5%, demonstrating the sensor’s practical applicability for early gastric cancer screening. This work represents a significant advancement in developing rapid, sensitive, and cost-effective diagnostic tools for gastric cancer surveillance.