An antifouling biosensor based on superhydrophilic materials for carcinoembryonic antigen detection in complex human serum

Inspired by natural micro-nano structures, this work develops a novel antifouling electrochemical biosensor based on hierarchical micro-nano materials with superhydrophilic property for highly sensitive and reliable detection of carcinoembryonic antigen (CEA) in complex human serum. This superhydrophilic electrode surface features a hierarchical micro-nano architecture of AuNPs/Cu-MOFs/Cu(OH)₂ and antifouling peptides, significantly enhancing the electrode surface's roughness and hydrophilicity, endowing the electrode surface with exceptional resistance to nonspecific adsorption of biomacromolecules in serum. The aptamer-modified micro-nanostructured electrode is built as the biosensor, enabling efficient access of target CEA molecules to the electrode surface and generating electrochemical signals with favorable sensitivity and reliability. This biosensor demonstrates superior sensing performances with the detection concentration ranging from 1 pg/mL to 0.01 μg/mL and a limit of detection (LOD) as low as 0.34 pg/mL. Moreover, the analytical results from human serum samples are consistent with those obtained via enzyme-linked immunosorbent assay (ELISA) method, confirming the sensor's accuracy and reliability. This work provides a promising strategy for designing antifouling sensor with enhanced applicability in clinical diagnostics and biomarker analysis.