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

•A novel sensor S-CHIT/ABPE was prepared which for the simultaneous detection of catechol (CC) and hydroquinone (HQ).•High sensitivity, repeatability, reproducibility and cheaper price of the sensor were obtained.•Good linear concentration ranges of CC and HQ is 0.6–80 μM and 1.0–80 μM, and with low detection limits were 0.1 μM and 0.4 μM respectively.•The sensor was successfully applied to the detection of CC and HQ in water samples.