Design and Optimization of Biosensor for Pyruvate Quantification

In this work, an amperometric pyruvate-sensitive biosensor was developed and optimized. A platinum disk electrode was used as an amperometric transducer. The bioselective element of the biosensor is based on the pyruvate oxidase enzyme immobilized with PVA-SbQ polymer by photopolymerization. The optimal immobilization conditions (enzyme and photopolymer concentrations, duration, and intensity of photopolymerization) were selected. The optimal concentrations of cofactors and cosubstrates (phosphate ions, thiamine pyrophosphate, and magnesium ions (Mg²⁺) were chosen to ensure the best sensitivity of the developed biosensor to pyruvate. After optimizing the design of the bioselective element and the immobilization process, the reproducibility of the biosensor manufacturing procedure was investigated (RSD = 12.5%). To assess the prospects of the developed biosensor, its main analytical characteristics were analyzed. The linear range of the biosensor was from 10 to 500 μM pyruvate, and the sensitivity was 66 nA/mM. The minimum detection threshold was 1.57 μM pyruvate. The obtained data indicate the technical feasibility and prospects of using the developed biosensor for determining the concentration of pyruvate in real multicomponent biological samples.