An optical sensor based on pyranine immobilized on aminopropyl-modified mesoporous silica films was developed for paraquat detection in aqueous solutions.An electrochemically assisted self-assembly method was used to deposit mesoporous silica film on fluorine-doped tin oxide glass.The obtained films were modified with various concentrations of 3-aminopropyl triethoxysilane (APTES) before the immobilization of pyranine.Cyclic voltammetry, scanning electron microscopy, transmission ut solution gel for cats electron microscopy, Fourier transform infrared spectroscopy, and fluorescence spectroscopy were used to characterize the films.
Pyranine-immobilized films gave an emission at 506 nm with an excitation at 450 nm.The fluorescence signal was quenched in the presence of paraquat.The films modified with 3% APTES provided the optimum response to paraquat.The developed films had a linear response to paraquat in the concentration range of 1 to 10 ppm at the optimum conditions, with a detection limit of 0.
80 ppm.The developed method was used to quantify michael harris sunglasses paraquat in sugarcane peel and tap water samples with satisfactory results.