oxidasebased

Oxidase-based refers to approaches that rely on oxidase enzymes to catalyze the oxidation of a substrate using molecular oxygen as the electron acceptor. In most systems, the oxidation event or its product is converted into a detectable signal, enabling measurements of substrate concentration, enzyme activity, or metabolic state.

Common oxidase enzymes include glucose oxidase, lactate oxidase, urate oxidase, and xanthine oxidase. These enzymes are widely used in clinical diagnostics, food quality control, and environmental monitoring. In biosensors, oxidases may be immobilized on electrodes; detection can be amperometric through the oxidation of produced hydrogen peroxide, colorimetric via peroxidase-coupled chromogenic reactions, or fluorometric through substrate-derived fluorescence.

Often, oxidase-based sensors rely on oxygen as the terminal electron acceptor, making results sensitive to ambient oxygen levels. A common approach couples hydrogen peroxide generation to a secondary reaction that yields a measurable signal. Enzyme immobilization, co-immobilized mediators, and electrode materials influence sensitivity, response time, and stability.

Advantages include specificity, mild operating conditions, and rapid readouts. Limitations include dependence on oxygen concentration, potential interference from reducing substances, H2O2 stability, and the need for calibration and storage considerations for enzymes.