Transcutaneous lactate monitoring based on a micro-planar amperometric biosensor

A transcutaneous lactate monitoring method has been developed by combining a suction effusion fluid (SEF) collecting technique with a micro-planar amperometric biosensor. SEF is directly collected by a weak suction through the skin from which the stratum corneum has been removed. A micro-planar biosensor, has also been developed for determining lactate concentrations in very small samples. The biosensor utilizes a lactate oxidase immobilized membrane on a micro planar platinum electrode to yield a lactate sensor. The sensor is based on amperometric detection of hydrogen peroxide generated by the lactate oxidase-catalyzed oxidation of l-lactate. The linearity of the lactate sensor response was obtained from 0.5 mM to 25 mM and the response time was about 10 s. The sensor was applied to the SEF lactate measurement of a rabbit during induced high lactate levels. Lactate concentrations measured with SEF showed good correlation with those obtained directly from whole blood. This result suggests the feasibility of transcutaneous lactate monitoring without the use of blood sampling.