In this work, an amperometric biosensor for lactate determination based on a Sonogel-Carbon transducer has been developed and evaluated using the lactate oxidase enzyme coated with a multipolymer layer as a bioreceptor. The biosensor obtained had adequate sensitivity (4.16 x 10^-8 A mM^-1) and a wide linear working range (0.2-20 mM) that allowed the determination of lactate at high concentrations without showing enzyme saturation phenomena. The selectivity of the biosensor was also verified using interferents commonly observed in physiological samples. Moreover, a microfluidic cell was designed and fabricated to allow the determination of lactate with the proposed biosensor in a continuous regime. In the end, the viability of the biosensor was tested with the proposed flow system using synthetic samples, obtaining excellent results.