A Simple Fluorescence Sensor Based on Merocyanine 540-MnO2 System to Detect Hypochlorite

Merocyanine 540 (MC540)-MnO2 system-based fluorescence sensor is reported as an anion sensor in aqueous solution. MnO2 was synthesized in the presence of KMnO4 and CTAB using MOPS buffer. The formation of MnO2 was first confirmed by a color change and characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and absorption spectroscopy techniques. Next, the interaction of MC540 with MnO2 in aqueous solution was investigated at various conditions by UV–Vis. absorption and fluorescence spectroscopy and the MC540-MnO2 system to use in fluorescence sensor studies was determined. The sensing ability of the MC540-MnO2 was tested to detect anions as a “Turn-off” fluorescent sensor. The MC540-MnO2 revealed to be high selectivity and sensitivity to detect ClO- ions without being affected by the other thirteen anions. The detection limits for ClO- were evaluated in two different concentration ranges and calculated to be 0.14 µM at 0.33-4.46 µM and 0.38 µM at 5.06-14.30 µM, respectively. Furthermore, interference experiments for ClO- in the presence of other anions were carried out, and it turned out that the system could detect ClO- without being affected by other anions.