A new FRET-based fluorescent probe: Colorimetric and ratiometric detection of hypochlorite and anti-counterfeiting applications

Hypochlorite (ClO − ), as the main component of widely used disinfectants in daily life, comes into closer contact with the human body, which can lead to a number of diseases. The high-performance method is increasingly needed to detect ClO − in our daily life. In this report, we successfully synthesized a FRET ratiometric fluorescent probe (NDAC) containing benzoxadiazole moieties and coumarin moieties bound via ethylenediamine. As expected, NDAC has excellent selectivity and anti-interference ability toward ClO − , and the ratio of fluorescence intensity (I 471 nm /I 533 nm ) has a very good linear relationship with the concentration of ClO − , with a wide linear range (2.5–1750 μM) and low detection limit (0.887 μM). Furthermore, we have successfully applied it for the quantitative detection of ClO − in water samples in daily life. At the same time, there is a very clear change in the fluorescence color after the reaction of the NDAC with ClO − . The blue/green value (B/G) of this color change also shows a very good linear relationship to ClO − (5.0–1000 μM). Therefore, the NDAC has also been successfully used for test strip detection and quantitative detection of ClO − in actual samples through smartphone-based fluorescence image analysis, and this method can provide faster, more convenient and more accessible detection. In addition, NDAC sensors also have potential applications in the field of information anti-counterfeiting.