Novel L-cysteine-functionalized Au@MnO2/MoO3 nanocomposites for electrochemical detection of apoptosis-related proteins in immunogenic cell death of patient-derived lung cancer cells

This study presents the development of a label-free electrochemical immunosensor for detecting apoptosis-related proteins, calreticulin (CRT) and high-mobility group box 1 (HMGB1), in the context of immunogenic cell death (ICD). The immunosensor utilizes a novel L-Cys/Au@MnO₂/MoO₃ nanocomposite-modified screen-printed carbon electrode (SPCE) to investigate the electrochemical detection of HMGB1, a topic with limited prior research. The successful assembly of the immunosensor was confirmed through XRD, SEM, and XPS analyses. The strong biomolecular adsorption capability of Au nanoparticles, combined with the superior charge transfer properties of MnO₂ and MoO₃, enhances the electrochemical performance of the immunosensor. The immunosensor achieved low detection limits (LOD) of 0.5391 pg/mL for CRT and 0.849 pg/mL for HMGB1, along with broad dynamic linear ranges of 0.001 to 10 ng/mL and 0.001 to 1000 ng/mL, respectively, highlighting the excellent selectivity, reproducibility, and stability of this novel immunosensor. With higher drug concentrations and extended treatment durations, increased levels of ICD biomarkers were observed, underscoring the potential of the immunosensor for monitoring drug efficacy and its applicability in personalized medicine.