Rapid and highly selective electrochemical sensor based on ZnS/ Au-decorated f-multi-walled carbon nanotube nanocomposites produced via pulsed laser technique for detection of toxic nitro compounds

Novel ZnS/Au/f-multi-walled carbon nanotube (MWCNT) nanostructures were produced via a pulsed laser assisted technique followed by a wet chemical process. ZnS nanospheres were synthesized via pulsed laser ablation of a Zn target in DMSO, which was used as a solvent and sulfur source. Notably, no additional sulfur sources, surfactants, or reducing agents were used during the synthesis. The structure and morphology of the prepared materials were characterized by X-ray diffraction, micro-Raman spectroscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, field emission scanning electron microscopy, and high-resolution transmission electron microscopy. The fabricated electrochemical sensor based on ZnS/Au/f-MWCNT nano composites exhibited rapid and highly selective detection of a toxic pollutant, namely 4-nitrophenol (4-NP). Linear sweep voltammetry analysis revealed that the optimized ZnS/Au10/f-MWCNT3 nanocomposite displayed a wide linear dynamic response (10-150 mu M) with high sensitivity (0.8084 mu A mu M? 1 cm? 2) and low limit of detection (30 nM). The excellent 4-NP sensing performance of the modified electrode was attributed to the availability of numerous active sites (electrochemical surface area = 0.00369 mu F cm? 2) and an enhanced electron transfer rate. Interference and stability studies were also conducted. A 100-fold excess of competing ions (Na+, K+, Mg2+, Cl?, NO3?, 4-AP, AA, and 2-NP) did not interfere with the selective detection of 4-NP. The newly fabricated ZnS/Au10/f-MWCNT3 nanocomposite could be an effective sensor for the selective and sensitive detection of toxic organic nitro compounds. Superscript/Subscript Available

Automated summary

Novel ZnS/Au/f-MWCNT nanostructures were successfully fabricated and used to develop an electrochemical sensor capable of selectively and sensitively detecting the toxic organic compound 4-nitrophenol (4-NP). The optimized nanocomposite exhibited a wide linear dynamic response, high sensitivity, and low detection limit, attributed to numerous active sites and enhanced electron transfer rate. Interference and stability studies demonstrated the sensor's ability to selectively detect 4-NP even in the presence of competing ions.