Peptide-integrated bovine serum albumin hydrogel as a synergistic antifouling strategy for electrochemical detection of cardiac troponin I in serum.

Electrochemical biosensors often suffer from biofouling in complex biological samples, which compromises detection accuracy and limits their practical applicability. To address this problem, we developed a synergistic antifouling biosensor by integrating the bovine serum albumin hydrogel (BSAG) with a designed multifunctional peptide for the detection of cardiac troponin I (cTnI) in complex biofluids. A stable and versatile antifouling layer was constructed via a facile one-step crosslinking method based on bovine serum albumin (BSA), and the amino-enriched surface of BSA enabled the secondary grafting of a multifunctional peptide that combines with anchoring, antifouling, and recognition properties. This approach not only enhanced the antifouling performance and durability of the coating, but also avoided potential interference associated with the introduction of exogenous recognition molecules. The cooperative antifouling performance of this hierarchical interface was systematically validated through electrochemical measurements and fluorescence imaging, demonstrating excellent resistance to biofouling in various biological fluids. The fabricated biosensor possessed long-term stability, high sensitivity and a broad linear response was obtained within the range of 0.1 pg mL-1 - 100 ng mL-1, accompanied by a low detection limit of 0.042 pg mL-1. Overall, this study presents a robust and generalizable interface engineering strategy that significantly enhances biosensor antifouling performance and analytical reliability, highlighting its strong potential for clinical monitoring in complex biological environments.