Temperature-controlled electrochemical sensor based on environmentally responsive polymer/BiPO4/BiOCl/multi-walled carbon nanotube composite for the detection of catechol in water

Catechol is a phenolic environmental pollutant that is highly toxic to living organisms and is released into the environment, where it is difficult to degrade in the ecosystem, thereby contaminating the environment and groundwater. Here, P(NIPAM-co-BMA)/BiPO 4 /BiOCl/MWCNTs nanocomposites were synthesized, and a temperature-controlled "on/off" electrochemical sensor was constructed. In addition, the P(NIPAM-co-BMA)/BiPO 4 /BiOCl/MWCNTs/GCE sensor shows good thermal sensitivity and electrochemical detection of catechol. Reproducible "on/off" switching on the CVs curve can be achieved by controlling the temperature of the solution. Under optimal conditions, the sensor was able to detect catechol in the linear range of 0.5–86.51 μM with a limit of detection of 0.2 μM (S/N = 3). Satisfactory results were obtained for the detection of natural environmental samples (tap water). In addition, the redox mechanism and electrochemical reaction sites of catechol were investigated by scanning rates. This work demonstrates for the first time the combination of temperature-sensitive polymers, bismuth-based compounds and multi-walled carbon nanotubes as electrochemical sensors for the detection of catechol, opening a new window for the sensitive detection of catechol. At the same time, the constructed switch-like electrochemical sensors can be better applied to different special scenarios.