A nitration reaction-based ratiometric chromo-fluorogenic BODIPY probe for nitrite (NO2−) detection in water

Abstract

Nitrite (NO₂⁻) is an essential ion which is involved in the biochemical cycle of nitrogen in nature and cell signaling pathways in animals and plants. Moreover, it is a critical inorganic material in many industries including chemicals, food, and pharmaceuticals. However, excessive industrial use of this ion leads to long-term negative impacts on the environment and the long-term exposure to NO₂⁻ might cause adverse health effects in humans via the formation of N-nitrosamines. Hence, the development of new sensing materials and detection methods for early detection and quantification of NO₂⁻ is of great importance. In this study, we propose, for the first time, a novel ratiometric chromo-fluorogenic detection method for the quantification of NO₂⁻ through the nitration of a monostyryl BODIPY derivative. This probe shows high selectivity, quick response (< 100 s) and a low detection limit (750 nM). With the addition of NO₂⁻, the pink color of the solution changed to light brown and the orange fluorescence turned to green with a 60 nm hypsochromic (blue) shift. In addition, the sensitivity of the probe to NO₂⁻ has been further evaluated by using tap and natural spring water samples and high recovery rates (91–115%) were obtained. We believe that our system, with increasing analytical sensitivity and accuracy by ratiometric detection, has great potential in accurate detection of NO₂⁻ with high precision and selectivity.