Salicylaldehyde functionalized chitosan for electrochemical sensitive sensor: Simultaneous determination of catechol and hydroquinone

Salicylaldehyde functionalized chitosan (S-CHIT) was prepared and electrochemical sensor based on the above material and acetylene black paste electrode (ABPE) were constructed. A new method for the simultaneous detection of catechol (CC) and hydroquinone (HQ) was established. The results of Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) showed that S-CHIT had been successfully synthesized and attached to the surface of ABPE. Cyclic voltammetry (CV) and second-order derivative linear sweep voltammetry (SDLSV) were used to investigate the electrochemical behaviors of CC and HQ on the S-CHIT/ABPE. In 0.1 M H2SO4 solution, CC and HQ produced a pair of reversible redox peaks with good shape on the modified electrode. The quantitative determination of CC and HQ was performed by SDLSV using the oxidation signal. The difference of the oxidation peak potentials between CC and HQ was 112 mV. In the presence of 50 µM of the respective isomer, the linear concentration range of CC and HQ is 0.6 μM to 80 μM and 1.0 μM to 80 μM respectively, and the corresponding detection limits are 0.1 μM and 0.4 μM. The method was applied to the simultaneous determination of CC and HQ in water samples. The results show that S-CHIT/ABPE is a promising electrochemical sensor for the simultaneous detection of CC and HQ.