Amperometric biosensor modified with platinum and palladium nanoparticles for detection of lactate concentrations in wine

Abstract

Detection of the lactate content is of great importance in clinical diagnostics, fermentation industry, and control of the quality of food products. The work was aimed at the development of a sensitive element of the amperometric biosensor, based on enzyme lactate oxidase and carbon electrodes modified with platinum and palladium nanoparticles (Pt&Pd), for the lactate analysis in the presence of interfering substances. The voltamperometric characteristics of the modified sensor were studied, the enzyme stabilization was carried out. An influence of the medium parameters on the biosensor operation was comprehensively investigated. The working characteristics of the biosensor were thoroughly analyzed, its stability and selectivity were investigated. An increase in the bioselective membrane activity as a result of using Pt&Pd nanoparticles was shown. The developed biosensor for the measurement of lactate concentration is characterized by the linear range of 0.05–0.8 mM, the lower detection limit 0.1 µM and sensitivity of 3.03 nA mM−1 cm−2. The main interferents were shown to have no effect on the work of created lactate biosensor. The lactate content in several types of wine and must was determined with created biosensor (lactate concentration in wine ranges from 0.5 to 5 g/l), and the results were compared with those obtained by the traditional spectrophotometric method; good correlation was shown (the correlation coefficient R2 = 0.98). The developed sensor can be used in winemaking for selective detection of lactate in raw material during fermentation and control of the final quality of wine.