A fluorescence switch-on approach to detect hydrazine in aqueous solution at neutral pH

A new fluorescent probe capable of reliable detection of hydrazine under environmentally friendly conditions with high specificity and sensitivity was developed. 3,6-Diacetoxyfluoran (FDA), a readily commercially available compound, is explored for fluorescence switch-on detection of hydrazine in this work. FDA can undergo hydrazinolysis and transform into fluorescein in aqueous solution at neutral pH, resulting in distinct optical changes from colorless to green and switch-on fluorescence which allows for establishing a new method for sensitive detection of hydrazine. Under optimum conditions described in this work, the enhancement of fluorescence at 515 nm was linearly proportional to the concentrations of hydrazine ranging from 1.25 to 25.00 mu M with a correlation coefficient of R-2 = 0.9959 and a detection limit as low as 31 nM. The relative standard deviation of twelve replicate measurement samples was 5.4% for 12.5 mu M hydrazine. The proposed method is convenient, low cost and free of complex equipment, making it possible to successfully determine hydrazine in four real samples containing distilled water, tap water, isoniazid and plasma. Furthermore, the hydrazine probe would be a promising candidate capable of naked-eye visualization of gaseous hydrazine by simple operations.