Development of an enzymatic biosensor to determine eugenol in dental samples

A GCE/CRGO-βCD's/ADA-SPE/AuNPs biosensor was successfully developed to determine eugenol in dental samples. The optimal conditions to construct the biosensor were obtained from an experimental design based on the response surfaces methodology. The GCE/CRGO-βCD/ADA-SPE/AuNPs biosensor exhibited a very good analytical performance for the quantification of eugenol. Thus, it shows a linear range between 1.3 × 10^-8 and 1 × 10^-5 mol L^-1, with a sensitivity of (5.3 ± 0.3) x 10^-3 A mol^-1 L. The limits of detection and quantification were 4 × 10^-9 mol L^-1 and 1.3 × 10^-8 mol L^-1, respectively. Biosensors had an intraday and inter day reproducibility of 5% and 8%, respectively. The repeatability was of 3%, and the stability was 21 days (a decrease of 30% in current responses was observed after the fourth week). Recovery studies were performed in order to validate the proposed method. Recovery percentages were between 94 and 108%. A value of the apparent Michaellis-Menten constant, K_M^app, of 3.1 × 10^-6 mol L^-1 was obtained using both Lineweaver-Burk and Eadi-Hofstee methods.