Inhibition of fluorescence enhancement of benzimidazole derivative on doping ZnO with Cu and Ag

A sensitive benzimidazole derivative fluorescent sensor for nanoparticulate ZnO has been designed and synthesized. The synthesized sensor emits fluorescence at 360 nm and this fluorescence is selectively enhanced by nanocrystalline ZnO. This technique is sensitive to detect and estimate ZnO at micro molar level. Doping ZnO with Cu does not hamper the sensitivity but Ag-doping significantly reduces the same. The nanocrystalline ZnO, Ag doped ZnO and Cu doped ZnO have been synthesized by sol–gel method and characterized by powder X-ray diffraction, scanning electron microscopy and UV–vis diffuse reflectance, photoluminescence and electrochemical impedance spectroscopies.