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 8.0 μmol L−1 with a detection limit as 0.01 μmol L−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.