Innovative Multipolymer-Based Electrochemical Biosensor Built on a Sonogel–Carbon Electrode Aiming for Continuous and Real-Time Lactate Determination in Physiological Samples: A New Scenario to Exploit Additive Printing

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 × 10−8 A mM−1) and a wide linear working range (0.2–20 mM) that allowed for 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.