Biopolymer Cooperation for Sustainable High‐Performance Oxidase‐Based Biosensing with the Simplest Possible Readout of Substrate Conversion

Abstract For sustainable high‐quality biosensor preparation, the biopolymers zein and gelatin are placed on Pt electrodes as base‐ and top‐coats, respectively, through simple drop‐and‐dry addition. The gelatin top‐coat of the biocompatible sandwich supports covalent external attachment of glucose oxidase (GOx), ensuring easy access of substrate to enzyme, while the lower, selectively permeable zein base‐coat protects electro‐oxidative detection of enzymically‐produced hydrogen peroxide from interferents. The functional cooperativity between gelatin‐GOx immobilization and molecular filtering by zein produced signal linearity up to 1 mm glucose, a sub‐µm practical detection limit, a rapid response time, a long shelf‐life, and excellent glucose analytical quality testing even with serum samples with intentionally elevated levels of interferents. This demonstrates for the first time the exceptional power of the cooperative action of two natural polymers in the ecofriendly improvement of a biosensor. The excellent performance of the novel biosensor design is confirmed here using GOx as a model, however, its application to other enzymes, antibodies, and DNA is feasible, offering economical biosensing while utilizing green functional materials. Moreover, the successful establishment of the cooperative dual biopolymer functionality on mass‐fabricated commercial screen‐printed electrode platforms verify the essential suitability of this methodology for portable clinical and personal health care monitoring.