Chitosan hydrogel-stabilized red blood cell membrane interface for robust electrochemical sensing of environmental contaminants

The development of robust biomimetic interfaces remains challenging due to the inherent instability of native cell membranes when integrated into functional devices. Herein, we reported a bio-based functional composite in which a chitosan-derived conductive hydrogel served as a multifunctional matrix to achieve unprecedented stabilization of red blood cell membranes (RBCMs). Leveraging the three-dimensional polycationic network and abundant amino groups of this natural polysaccharide, the hydrogel electrostatically anchored RBCMs while preserving their native fluidity and membrane-bound acetylcholinesterase conformation-overcoming a long-standing bottleneck in biomembrane-based material engineering. Integration of carboxylated multi-walled carbon nanotubes endowed the composite with efficient electron transfer capability without compromising biocompatibility. The resulting biomimetic interface retained 85.8% of its initial electrochemical response after 7 days of continuous operation and enabled sensitive detection of organophosphate pesticides in real agricultural samples (apples, oranges, and tomatoes). This work established chitosan hydrogel as a versatile bio-based platform for constructing stable biomembrane composites, expanding the application scope of natural polysaccharides in functional material design for environmental monitoring.