Green-to-Blue Fluorescence Sensor on Pesticide Starane Based on Bis-Tetraphenylimidazole

Abstract

As starane is a pesticide used widely in agriculture, the simple, rapid and on-site detection for starane is extremely anticipated to avoid the harm of starane to human health and the environment. In this work, a diamino naphthalene Schiff-base bridging bis-tetraphenylimidazole (Bis-TPI) was prepared as an effective fluorescence sensor on pesticide starane with very low detection limitation. Bis-TPI showed the weak green fluorescence in aqueous media but strong blue fluorescence after binding starane with good sensing selectivity for starane among various ions and pesticides. The detection limitation was as low as 0.015 μM, which is the smallest value of fluorescence sensor for starane. The 1:1 binding mechanism was clarified as that starane was bound in the opening cavity of Bis-TPI based on hydrogen bond, π-π stacking and hydrophobic action. Bis-TPI was successfully used to detect starane on test paper, fresh leaves and the real water samples of starane, confirming the good application potential on rapid, simple and on-site examination of starane in agriculture and daily life.

Keywords: Fluorescence, sensor, starane, tetraphenylimidazole