A signal-amplified electrochemiluminescence immunosensor based on AgInZnS QDs with Au NPs/Co-ZnO NBs as a co-reaction accelerator for the detection of CA242

A highly efficient electrochemiluminescence (ECL) immunosensor was developed for the detection of tumor marker CA242 using biocompatible AgInZnS quantum dots (AIZS QDs) as anodic luminophores coupled with a gold nanoparticle (Au NP)/Co-doped ZnO nanoblock (Co-ZnO NB) composite as a photoelectrically enhanced co-reaction accelerator. The Co-ZnO NB composite provided structural stability and improved catalytic performance by introducing additional active sites, enhancing the electrical conductivity of ZnO, and maintaining excellent bioactivity and configuration stability under complex physiological conditions. The integration of Au NPs further facilitated electron transfer within the ECL system and amplified the ECL emission of AIZS QDs by promoting both the dissociation of the co-reactant triethylamine (TEA) and the charge transfer process. The synergistic effects significantly amplified the ECL signal, improving the sensitivity and specificity of the sensor for CA242 detection. Validation with clinical blood samples confirmed its superior performance and reliability, demonstrating its potential as an effective diagnostic tool for clinical applications.