Development of carbon-based nanocomposite biosensor platform for the simultaneous detection of catechol and hydroquinone in local tap water

The significant aspect of this work is to develop a nanocomposite biosensor based on the combination of Fe3O4 nanoparticles (NPs)-multi-walled carbon nanotubes (MWCNTs) (Fe3O4-MWCNTs), tyrosinase (TYR), and silica sol-gel (SiSG). The obtained material was drop cast on the glassy carbon electrode (GCE) to attain a nanocomposite biosensor (SiSG-TYR/Fe3O4-MWCNTs/GCE). The surface morphology of Fe3O4-MWCNTs was characterized by FE-SEM, TEM, and EDS techniques. The analytical performance of the electrochemical biosensor was evaluated by using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The SiSG-TYR/Fe3O4-MWCNTs/GCE was applied as an efficient biosensor for the simultaneous determination of catechol (CC) and hydroquinone (HQ). A good linear relationship was figured out between the peak currents and analyte concentrations from 1.5 to 30 mu M and 1.5-40 mu M for CC and HQ with detection limits down to the concentrations of 0.055 and 0.057 mu M, respectively. Several kinetic parameters such as charge transfer coefficient, the heterogeneous rate constant, and the number of electrons involved were successfully calculated. The developed biosensor exhibited satisfactory repeatability, reproducibility, good stability, and anti-interference performance. The proposed biosensor was efficiently used for the detection of CC and HQ in spiked local tap water with satisfactory results.

Automated summary

This work developed a nanocomposite biosensor based on Fe3O4-MWCNTs, TYR, and SiSG for simultaneous detection of CC and HQ, showing good electrochemical and biosensing performance.