Synthesis of hierarchically porous 3D polymeric carbon superstructures with nitrogen-doping by self-transformation: a robust electrocatalyst for the detection of herbicide bentazone.

Bentazone (BEZ) is one of the utmost selective problematic contact-past herbicide with high toxicity for humans owing to feasible contamination of surface and ground water. In this work, an electrochemical sensor has been developed for the sensitive detection of BEZ, based on hierarchically porous three-dimensional (3D) carbon superstructures (CS)-modified electrodes. The CSs (namely, CSHEX, CSPY, CSACN, and CSNOS) were prepared by the pyrolysis process from organic porous polyacrylonitrile (PAN) superstructure particles (namely, PANHEX, PANPY, PANACN, and PANNOS) obtained by free radical polymerization method using different solvents (hexane, pyridine, acetonitrile, and also no solvent). The assembly with the working electrode of CSs causes the electrocatalytic BEZ oxidation by rapid electron transfer compared to the PAN superstructures and bare electrodes. Intriguingly, compared to all electrodes, CSHEX-modified electrode showed the superior electrochemical detection of BEZ at a working potential of 0.99 V (vs. Ag/AgCl), very low detection limit (0.002 μM), wide dynamic linear range (0.03 to 200 μM), high sensitivity (9.95 μA μM-1 cm-2), and excellent reliability. The advanced sensors displayed an intensification of oxidation peak current of BEZ with high selectivity, remarkable sensitivity, and reproducibility for BEZ detection and received satisfactory outcomes designating the application of sensors for the determination of BEZ in river water samples.