A biosensor based on gold nanoparticles, dihexadecylphosphate, and tyrosinase for the determination of catechol in natural water

•A new biosensor is proposed using a GCE modified with Au nanoparticles and Tyr within DHP.•The proposed electrode can be easily prepared and showed low detection limit.•The Tyr-AuNPs-DHP/GCE was successfully applied for catechol determination in fresh water samples.

In this work, a biosensor using a glassy carbon electrode modified with gold nanoparticles (AuNPs) and tyrosinase (Tyr) within a dihexadecylphosphate film is proposed. Cystamine and glutaraldehyde crosslinking agents were used as a support for Tyr immobilization. The proposed biosensor was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and cyclic voltammetry in the presence of catechol. The determination of catechol was carried out by amperometry and presented a linear concentration range from 2.5 × 10−6 to 9.5 × 10−5 mol L−1 with a detection limit of 1.7 × 10−7 mol L−1. The developed biosensor showed good repeatability and stability. Moreover, this novel amperometric method was successfully applied in the determination of catechol in natural water samples. The results were in agreement with a 95% confidence level for those obtained using the official spectrophotometric method.

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