Multi-Purpose electrochemical tyrosinase nanobiosensor based on poly (3,4 ethylenedioxythiophene) nanoparticles decorated graphene quantum dots: Applications to hormone drugs analyses and inhibition studies

摘要

In this work, a novel multi-purpose amperometric nanobiosensor based on tyrosinase enzyme for the determination of phenolic compounds, catechol, epinephrine, and norepinephrine, was developed. This novel nanobiosensor was prepared from Tyrosinase enzyme immobilization in poly (3,4 ethylenedioxythiophene) nanoparticles decorated graphene quantum dots platform via crosslinking with glutaraldehyde. Parameters that can affect biosensing, such as graphene quantum dots, poly (3,4 ethylenedioxythiophene) nanoparticles, tyrosinase quantities, pH, and temperature, were optimized. Under optimized conditions, determination of phenolic compounds was achieved in the range 0.005-11 μM for catechol, 0.2-12 μM for epinephrine, and 0.1-2.5 μM for norepinephrine. Limit of detection values were found as 0.002 μM, 0.065 μM, 0.035 μM for catechol, epinephrine, and norepinephrine, respectively, with acceptable repeatability and reproducibility results. Moreover, the developed nanobiosensor was further successfully utilized to follow inhibition of tyrosinase by a non-steroidal anti-inflammatory drug, diclofenac, with different incubation times and concentration levels. Hence, I_(50) was reported as 4.87 mM diclofenac. The optimized biosensor was also applied for the detection of epinephrine and norepinephrine in pharmaceutical dosage forms, catechol from human serum.