A novel fluorescent chemodosimeter, 1-(2-methoxybenzylidene)-4- phenylthiolsemicarbazide, was studied. In 90: 10 (v/v) mixture of CH3CN and water binary solution, it exhibits high selectivity toward Cu2+ but very low response toward other competitive cations. The Cu2+ promoting cyclization of the thiosemicarbazide to 1, 2, 4- triazole-3 (4H)-thione ring results in observation of the turn-on fluorescence.
