Dual Biosensor for Simultaneous Monitoring of Lactate and Glucose Based on Thin‐layer Flow Cell Screen‐printed Electrode

A simple and robust monitoring system for lactate and glucose detection is presented. The system is based on a suitable integrated screen‐printed electrode in thin layer flow cell design (TLFCL) to perform flow injection analysis. The TLFCL is consisted of a two working and one counter electrodes made of carbon and a silver pseudoreference electrode. Both working electrodes (WE) are first modified by graphene nanomaterials. Glucose sensor based on cellobiose dehydrogenase from the ascomycete Corynascus thermophilus (CtCDH) and lactate sensor based on lactate oxidase (LOx) are made on the first and second WE respectively. Both enzymes are entrapped in a photocrosslinkable poly(vinyl alcohol) bearing styrylpyridinium groups (PVA‐SbQ). The electrocatalytic signal of both sensors did not show any cross‐talking, whereas the linear quantification ranges of both glucose and lactate sensors are large enough for wine monitoring.