HAND-HELD LUMINOMETER WITH ECL-BASED BIOSENSOR FOR LACTATE DETERMINATION

A new hand-held luminometer for electrochemiluminescence (ECL)-based one-shot bioscnsor for lactate is described. The lactate recognition system is based on lactate oxidase and the transduction system consists of luminol, all reagents immobilized in a Methocel membrane. The measurement of ECL from a screen-printed electrode by a portable instrument designed and developed by the authors makes it possible to determine lactate concentration. The compositions of the membrane and reaction conditions have been optimized to obtain adequate sensitivity. The one-shot biosensor responds to lactate rapidly, with the typical ECL acquisition time being 3 min, with a linearized dependence whose dynamic range was from 9.10(-6) to 2.10(-3) M, a detection limit of 2.4.10(-6) M and a sensor-to-sensor reproducibility (relative standard deviation RSD) around 10% at the medium level of the range. The performance of the ECL one-shot biosensor and portable instrument was tested for the non invasive analysis of lactate in saliva, validating the results against a reference procedure.