Nickel foam decorated with ZnO nanocrystals using mesoporous silica templates for ultrasensitive electrogenerated chemiluminescence determination of diazinon

Herein we report a highly sensitive and novel diazinon pesticide sensor based on the cathodic electrogenerated chemiluminescence (ECL) of ZnO in the presence of peroxydisulfate for the first time. The proposed modified electrode was fabricated by decoration of the nickel foam electrode with zinc oxide nanocrystals. The silica templates were used as a morphology-controlling agent for modification of the Ni-foam electrode surface with zinc oxide nanocrystals. The physical morphology of the ZnO/Ni-foam electrode was carried out by electrochemical impedance spectroscopy, X-Ray diffraction analysis, field emission scanning electron microscopy and energy-dispersive X-ray analysis. The ultra-sensitive ECL method was successfully used for ultra-trace determination of diazinon. A good linear relationship was found between the ECL intensity and diazinon concentration within 3.0 x 10(-14) M to 8.0 x 10(-9) M, with a low detection limit (signal to noise ratio of 3) of 1.2 x 10(-15) M. The proposed cathodic ECL sensor exhibited superior performance toward the accurate determination of diazinon with good reproducibility and stability. These satisfactory results provided a promising potential in determination of diazinon in real samples and it was successfully used to detect diazinon in water and fruits samples and satisfactory recoveries were obtained.