Novel benzotriazole-based probes for the selective detection of Cu(II)

• A novel fluorescent probe - benzotriazole derivative system was constructed. And mono-substituted and di-substituted products generated by this reaction both can be used as fluorescent probe to detect Cu(II). • By exploring the spectral properties of the probe, It is shown that the probe has a low detection limit ( 3a :8.83 µM; 3b :8.62 µM; 3c :2.01 µM), which is far lower than the maximum allowable concentration of Cu(II) (20 µM) in drinking water. • The fluorescent probe has better selectivity to Cu(II), Ordinary cation has no significant interference to it. Moreover, ion competition experiments showed that the presence of other cations hardly affected the fluorescence response of Cu(II) to the probe. In this paper, a new kind of fluorescent probe - benzotriazole derivative system was constructed by amino derivatization reaction. By studying the spectral properties of the probe, we found that both the mono-substituted and di-substituted products of the reaction can be used as fluorescent probes for selective detection of Cu 2+ ion. Therefore, we can selectively obtain different kinds of fluorescent probes by adjusting the reaction conditions. And these probes have the advantages of low detection limit ( 3a : 8.83 µM; 3b : 8.62 µM; 3c : 2.01 µM) and high selectivity for other ions (Ca 2+ ,Co 2+ ,Zn 2+ ,Fe 3+ ,Cs + , K + ,Mg 2+ ,Ni 2+ ,NH 4 + ,Al 3+ ,Na + ,Cr 3+ ,Cd 2+ ). In addition, the fluorescence intensity of these probes responds linearly to [Cu 2+ ], and the presence of Cu 2+ ion can be sensitively detected by obvious fluorescence quenching.