An enzyme-assisted SERS immunoassay for detection of biomarkers in lung cancer using AgPb bimetallic core-shell nanoparticles

This study focused on synthesizing AgPb bimetallic core-shell nanoparticles (AgPb NPs) using a simple polyol reduction method and applying them for amplifying the signal in glucose oxidase (GOx)-assisted SERS immunoassays for sensitive and selective detection of carcinoembryonic antigen (CEA) as a main biomarker for lung cancer. Results of SERS monitoring demonstrated the redox activity of GOx in the presence of varying concentrations of hydrogen peroxide (H 2 O 2 ) using SERS. In the SERS immunoassay, glucose was oxidized by GOx to produce H 2 O 2 which triggered the oxidation of Ag in AgPd nanoparticles, which enhanced the SERS signal and promoted sensitivity for detecting low concentrations of CEA. The SERS spectra showed significant enhancement in the presence of AgPd NPs, indicating their effectiveness in signal amplification. Study the analytical performance indicated to obtain a limit of detection of 0.41 pg/mL for CEA and detection range from 1 pg/mL to 1000 ng/mL, demonstrating superior sensitivity compared to other reported methods. These factors collectively contributed to the exceptional performance of AgPd bimetallic nanoparticles in enhancing SERS signals and sensitivity, making them promising candidates for advanced detection applications. The study demonstrated the potential of this SERS immunoassay for clinical use, providing accurate CEA detection in lung cancer patient serum.