A colorimetric fluorescent probe for rapid and specific detection of nitrite

The method of fluorescent probes has been an important technique for detection of nitrite (NO₂ ^- ). As an important inorganic salt, excessive nitrite would threaten humans and the environment. In this paper, a colorimetric fluorescent probe P-N (1,2-diaminoanthraquinone) with rapid response and high selectivity, which could detect NO₂ ^- by visual colour changes and fluorescence spectroscopy is presented. The probe P-N solution (pH 1) changed from pink to colourless with the addition of NO₂ ^- and fluorescence intensity at 639 nm clearly decreased. Good linear exists between fluorescence intensities and NO₂ ^- concentrations for the range 0-16 μM, and the detection limit was 54 nM (based on a 3σ/slope). Moreover, probe P-N could also detect NO₂ ^- in real water samples, and results were all satisfactory. Probe P-N shows great practical application value for detecting NO₂ ^- in the environment.