Laccase modified GO/TiS2 nanocomposite based amperometric biosensor for (-)-epicatechin detection

In this study, 2-dimensional graphene oxide-titanium disulfide (GO/TiS2) nanolayers were synthesized, and the surface and size properties of nanolayers were investigated by transmission electron microscopy (TEM) technique. The nanolayers were used to modify the screen-printed electrode surface and applied as a micro-medium for Trametes versicolor laccase. The ability of this enzyme biosensor to detect the (-)-epicatechin has been demonstrated with a wide linear range (0.1–250 µM), LOD (0.073 µM), and sensitivity (0.3264 µAµM−cm−2). In addition, the biosensor exhibited excellent selectivity allowing selective detection of (-)-epicatechin in the presence of other polyphenolic compounds and high reducing currents sensitivity (vs Ag/AgCl) examined at −0.6 V. The proposed biosensor showed reproducibility, reusability, long-term storage stability, and applicability in actual food samples with recovery values close to 100 %. Also, Kmapp and Imax values ​​of the biosensor were determined as 2.245 µM and 0.757 µA, respectively.