DEVELOPMENT OF AMPEROMETRIC BIOSENSOR BASED ON LACTATE OXIDASE FOR LACTATE DETERMINATION

Abstract

The amperometric biosensor was developed for determination of lactate concentration. As a bioselective element we used the enzyme lactate oxidase, coimmobilized with bovine serum albumin on the surface of amperometric transducer by glutaraldehyde covalent crosslinking. The platinum disc electrodes (Ø = 500 µm) served as transducers. The developed biosensor was highly sensitive to lactate, with a minimum limit of determination of lactate concentrations 3 µM and linear range 5 µM to 300-350 mM. It was shown that the proposed biosensor was characterized by high response replicability during several hours of non-stop measurement (the accuracy of measurement RSD = 3.4%) and satisfactory operational stability for several days. Optimal conditions for biosensor storage were analyzed and defined. One-month storage in the buffer solution at + 4 °C resulted in less than 50% loss of the biosensor activity. The impact of parameters of buffer solution (capacity and ionic strength) on the biosensor operation was analyzed. It was shown that the developed biosensor based on lactateoxidase used can successfully be used for lactate analysis in real biological liquids