A universal oxygen scavenger for oxidase-based biosensors.

Zhang, Huijie; Saadeldin, Mohamed G; Buesen, Darren; Elfaitory, Hamzah; Burger, Jakob; Friebe, Vincent M; Honacker, Jonas; Vöpel, Tobias et al. · Sci Adv · 2025

basic_science · Level V

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Abstract

Oxidase-based electrochemical biosensors are widely deployed for point-of-use applications, yet oxygen interference remains a major challenge, substantially reducing sensing accuracy. Here, we developed a universal enzymatic O<sub>2</sub> scavenger composed of alcohol oxidase, catalase, and paraformaldehyde to eliminate O<sub>2</sub> within the sensor by converting it to water. Unlike other oxidases, alcohol oxidase exclusively uses O<sub>2</sub> as an electron acceptor, preventing interference with the electron transfer chain involving the sensing oxidase. We demonstrated the compatibility of this O<sub>2</sub> scavenger for calibration-free sensing of glucose, lactate, and creatinine in the concentration range relevant to human health. Without the O<sub>2</sub> scavenger, sensor readings were less than 50% of those under inert gas conditions. With the O<sub>2</sub> scavenger, the accuracy improved to 99%, even at low substrate concentrations. The general compatibility and performances of this alcohol oxidase-based O<sub>2</sub> scavenger unlock the full potential of oxidase-based biosensors for reliable point-of-use sensing.

Medical subject headings