席夫碱类荧光探针CH_3CN/H_2O体系检测Cu^(2+)离子

A Schiff base fluorescence probe for Cu^(2+) ion in CH_3CN/H_2O

以1-氨基-2-萘酚和2,4-二羟基苯甲醛为原料合成了席夫碱(2′,4′-二羟基苯亚甲基亚氨基)-2-萘酚(L),采用FT-IR,1 HNMR和ESI-MS对其结构进行了表征.在V(CH3CN)∶V(HEPES)=1∶1(pH=7.2)缓冲溶液中,研究了L对多种金属离子(Cu^(2+),Hg^(2+),Ag+,Pb^(2+),Cd^(2+),Zn^(2+),Ni ^(2+),Co^(2+),Fe^(2+),Al ^(3+),Mn^(2+),Ca^(2+),Mg^(2+),K+,Na+)的荧光响应性能.结果表明:L能够通过荧光猝灭响应选择性识别Cu^(2+),且几乎不受其他金属离子的干扰.在Cu^(2+)浓度为0~2.5×10^(-5)mol/L范围内,溶液荧光强度与Cu^(2+)浓度呈现良好的线性关系,据此计算L与Cu^(2+)的结合常数为3.33×10~4 L/mol,对Cu^(2+)的检出限为4.92×10-7 mol/L.L在实际水体中与Cu^(2+)在0~2.5×10^(-5) mol/L浓度下依然表现出较好的线性关系.

A Shiff base(2′4′-dihydroxyl phenylideneimino)-2-naphthol(L)was synthesized from 1-amino-2-naphthol and 2,4-dihydroxybenzaldehyde.The aim compound was characterized by FT-IR,1 HNMR and ESI-MS.In the solution of V(CH_3CN):V(HEPES)=1:1at pH 7.2,the fluorescence responses of Lto many metal ions(Cu^(2+),Hg^(2+),Ag+,Pb^(2+),Cd^(2+),Zn^(2+),Ni^(2+),Co^(2+),Fe^(2+),Al ^(3+),Mn^(2+),Ca^(2+),Mg^(2+),K+,Na+)were studied.The results indicate that Ldisplays a fluorescence quenching for Cu^(2+)with good selectivity and without obvious interferences by other metal ions.In the concentration range of Cu^(2+)from0to 2.5×10^(-5) mol/L,the fluorescence intensity of this solution shows a good linear relationship with theconcentration of Cu^(2+).Based on this curve,the binding constant between Land Cu^(2+)is 3.33×10~4 L/mol,and the detection limit of Lfor Cu^(2+)is calculated to be 4.92×10-7 mol/L.In natural water,Lalso shows a good linearity with Cu^(2+)in the concentration range of Cu^(2+)from 0to 2.5×10^(-5) mol/L.