Biossensor Modificado com Carbon Black e AuNPs em filme de DHP para Determinação Amperométrica de Catecol

Carbon Black (CB) is a low-cost amorphous carbon nanomaterial. It has a high relation between surface area and volume, which makes it an interesting material for electroanalytical applications [1]. The combination of CB with other nanomaterials like gold nanoparticles (AuNPs) is interesting for the electroanalytical applications because provides an improvement in the analytical response of the electrode [2]. Tyrosinase (Tyr) is a metalloenzyme that has been widely used in biosensors for the determination of phenolic compounds due to the simplicity and efficacy of electroanalysis against robust methods of analysis. Catechol is a phenolic compound widely used in industry and can be poured into the environment after the industrial process, causing serious environmental impact, as it is toxic to animals and plants [3]. AuNPs were synthesized using the Turkevich Method [4]. Figure 1 schematically shows the preparation of the Tyr-AuNPs-CB-DHP/GCE biosensor. Amperometry was employed to perform the catechol determination. The analytical curve presented a linear range between 2.49 × 10−7 to 3.10 × 10−5 mol L−1 , following the equation Ic (μA) = −0.16 + 0.58 [catechol] (μmol L−1 ) (r = 0.9997). The detection limit was 1.28 × 10−7 mol L −1 .