Flexible Electrochemical Lactate Biosensor

Lactic acid is a key indicator for trauma and exercise intolerance. It is the primary metabolically produced acid responsible for tissue acidosis that can lead to muscle fatigue. During intensive exercise, the muscles go through anerobic metabolism to produce energy. This leads to decreases in the blood flow of nutrients and oxygen to the muscles and increases in lactate production, which in turn cause lactic acidosis. Currently, changes in blood lactate concentrations are monitored by sensors that can be invasive via blood or wearable based sensors that use the enzyme lactate oxidase. Lactate oxidase produces hydrogen peroxide, which is a toxic byproduct and can foul the surface of the sensor. Here we present the development of a noninvasive wearable electrochemical lactate biosensor for the detection of lactic acid. This work presents the development of non- invasive wearable electrochemical lactate biosensor for detection of lactic acid. The bioelectrode comprised D-Lactate dehydrogenase (D-LDH) immobilized on multi-walled carbon nanotubes (MWCNTs) using polydimethylsiloxane (PDMS) as a flexible substrate platform. The lactate biosensor exhibited a dynamic linear range of 2 mM to 44 mM lactic acid with a good sensitivity of 189.89 μA/mM cm2. This electrochemical biosensor has the potential to be used for the real-time detection of lactate in the clinical, biological and sports medicine fields.