A poly-L-lysine-functionalized electrochemical immunosensor enables highly sensitive detection of tumor necrosis factor receptor-associated protein 1.

Tumor necrosis factor receptor-associated protein 1 (TRAP-1), a member of the mitochondrial heat shock protein family (HSP90), is essential for protein homeostasis, stress response, and cell cycle. TRAP-1 not only optimizes cellular energy production but also prevents cell death, thereby supporting the survival and proliferation of tumor cells. In addition to cancer, TRAP-1 has been associated with Parkinson's disease, certain autoimmune disorders, and abnormalities in the kidney and urinary tract. In this study, a unique and useful indium tin oxide-polyethylene terephthalate (ITO-PET)-based electrochemical biosensor is described for detecting the biomarker TRAP-1. The ITO-PET electrode, selected as the working electrode, is a highly advantageous semiconductor electrode material due to its ease of functionalization, low cost, flexibility, and stability. It also stands out as a favorable working electrode due to its ability to detect analytes at very low concentrations. Electrochemical impedance spectroscopy and cyclic voltammetry were used to evaluate the immunosensor, optimize operating parameters, and characterize the biosensing system. In addition to these characterization techniques, single frequency impedance measurements were used to investigate the interactions of anti-TRAP-1 with TRAP-1. To evaluate the clinical applicability of the immunosensor designed, commercially available real human serum samples were analyzed. In conclusion, the biosensor was characterized and shown to be sensitive, reliable, and reproducible across a large detection range (0.004-20 pg/mL).