Two fluorescent probes based on benzothiazole inner salt structure for detecting bisulfite, 2-{2-[4-(N,N-diethylamino)-phenyl]vinyl}-N-(3-sulfonatepropyl)-benzothiazole, inner salt (1) and 2-{2-[4-(N,N-diethylamino)-2-hydroxyl-phenyl]vinyl}-N-(3-sulfonatepropyl)-benzothiazole, inner salt (2), have been developed. The probes can specifically recognize bisulfite (HSO₃⁻) in HEPES-DMSO mixed solution (V_HEPES:V_DMSO = 1:9) with low detection limits (1, 75.6 nM; 2. 23.4 nM) and fast response rate (<60 s). The sensing mechanism investigation by ¹H NMR titration indicates that HSO₃⁻ attacks to CC double bond by nucleophilic addition reaction, which results in broken conjugated structure and quenched red fluorescence. Probe 2 with hydroxyl substituent group has higher sensitivity for HSO₃⁻ than probe 1, which is believed to be due to the synergistic effect from hydroxyl coordinating with HSO₃⁻. The probes also can be used to the determination of bisulfite in food products and real-water samples.

两种基于苯并噻唑内盐结构的荧光探针，用于检测亚硫酸氢盐，2- {2- [4-（N，N-二乙氨基）-苯基]乙烯基} -N-（3-磺酸基丙基）-苯并噻唑，内盐（1）和已经开发了2- {2- [4-（N，N-二乙氨基）-2-羟基-苯基]乙烯基} -N-（3-磺酸基丙基）-苯并噻唑，内盐（2）。探针可以特异地识别亚硫酸氢盐（HSO ₃ ^- ）在HEPES-DMSO混合溶液（V _HEPES：V _DMSO  = 1:9）具有低检测限（1，75.6纳米; 2 23.4纳米。）和快速响应速率（<60 s）。传感机制的研究^1个1 H NMR滴定表明，HSO ₃ ^-至C攻击通过亲核加成反应C双键，其结果在打破共轭结构和淬灭红色荧光。探头2具有羟基取代基团具有用于HSO更高的灵敏度₃ ^-比探针1，这被认为是由于从与羟基HSO协调的协同效应₃ ^- 。该探针还可用于测定食品和实际水样品中的亚硫酸氢盐。