A sensitive and low toxicity electrochemical sensor for 2,4-dichlorophenol based on the nanocomposite of carbon dots, hexadecyltrimethyl ammonium bromide and chitosan

•Nanocomposite based carbon dots, CTAB and chitosan were prepared and characterized.•A novel electrochemical sensor for the determination of 2,4-DCP was built.•The proposed sensor was more simple, low toxicity and environment-friendly. A novel and sensitive electrochemical sensor for 2,4-dichlorophenol (2,4-DCP) based on a nanocomposite of carbon dots (CDs), hexadecyltrimethyl ammonium bromide (CTAB) and chitosan (CS) was constructed through electrostatic self-assembly technology. The nanocomposite of CDs–CTAB–CS introduced a favorable access for the electron transfer and exhibited excellent electrocatalytic activity toward the oxidation of 2,4-DCP. Differential pulse voltammetry (DPV) was used for the quantitative determination of 2,4-DCP. Under the optimized experimental conditions, the oxidation peak currents of 2,4-DCP were proportional to its concentrations in the range from 0.04 to 8.0μmolL−1 with a detection limit as 0.01μmolL−1. The newly developed method was successfully applied for the determination of 2,4-DCP in waste water with satisfactory recoveries. This CDs–CTAB–CS modified electrochemical sensor provides an operational access to design simpler, low toxicity and environment-friendly sensors based on carbon dots.