A novel fluorescent probe based on phenothiazine for recognition of Ni2+ and ClO− and its applications

In order to specifically detect Ni2+ and ClO−, a double functional s-triazine-phenothiazine fluorescent probe (BPTD) was synthesized, in which the multiple nitrogen atoms in s-triazine and hydrazone connecting arm were used for recognizing Ni2+, sulfur atom in phenothiazine was used as the reaction site for recognizing ClO−. BPTD has excellent optical properties: a large Stokes shift (131 nm) and good stability in a wide pH range (3.00 ∼ 12.00). Compared to the two fluorophores (s-triazine and phenothiazine), fluorescence emission peak of BPTD produces a large red-shift. The spectral experimental results show that BPTD can detect Ni2+ (5 ∼ 80 μM) and ClO− (10 ∼ 40 μM) with high selectivity and strong anti-interference. Compared with the reported fluorescent probes for detection of Ni2+, BPTD can detect Ni2+ more sensitively (response time 2.5 min, red shift 26 nm, the limit of detection (LOD) 98 nM), and simultaneously achieve the goal of highly sensitive detection of ClO− (response time 20 s, blue shift 18 nm, LOD 96 nM). BPTD can be applied to qualitative and quantitative detection of Ni2+ and ClO− in actual water samples, and made into portable test paper for rapid detection of Ni2+ and ClO−.