A highly sensitive and regenerable electrochemical immunosensor chip for blood adiponectin detection.

As Type 2 Diabetes Mellitus (T2DM) has become one of the most severe public health burdens worldwide, it is of great importance to realize early screening and sensitive diagnosis. Adiponectin is widely recognized as a prominent biomarker of T2DM, which holds superior accuracy and sensitivity for early diagnosis owing to its inverse correlation in the reversible prodromal stage of the disease. This study presents a novel and reusable electrochemical immunosensor chip for adiponectin detection to facilitate early warning and intervention of T2DM. Adiponectin antibodies are immobilized on the working electrode, where the surface is modified by gold nanoparticles (AuNPs). The measurements show a high sensitivity of 3.03 μA/decade over 14 regeneration cycles, along with a broad linear range of 0.5-25,000 ng/mL and a low limit of detection (LOD) of 0.0093 ng/mL. Integrating the sensing unit into a flow cell not only enables low reagent consumption and continuous-flow operation, but also allows the immunosensor to demonstrate excellent repeatability, reproducibility, and strong anti-interference capability. Finally, the proposed immunosensor delivers precise measurements of real blood samples, which provides a foundation for future studies and practical applications in T2DM clinical diagnosis.