Lactate is a key molecule in the anaerobic energy system of humans, primarily considered as the biomarker for tissue oxidative stress. Heavy workout, sepsis, trauma and cancer cause excess lactate production in bio-fluids including sweat. Therefore, lactate measurement is integral for clinical emergencies, sports and general medicine. An enzymatic electrochemical biosensor comprising lactate oxidase immobilized on metal nanostructures is developed here for continuous monitoring of lactate. The sensing mechanism entails detection of H2O2 produced during enzymatic oxidation of lactate. Three kinds of metal nanostructures, viz. gold, copper, and platinum were tested as catalysts for electrochemical oxidation of H2O2to increase the electro-Activity and detection sensitivity. Scanning electron microcopy and cyclic voltametry were used to characterize the nanostructured biosensors. Results show that the platinum nanoflakes decorated electrode provides a better sensitivity and detection limit towards lactate detection by providing favorable microenvironment to retain the bioactivity of the enzyme.