【摘要】 采用电子吸收和荧光光谱研究了罗丹明B-5-硝基水杨醛(RhB-NSal)在无水乙腈和醋酸缓冲溶液中对Cu2+离子的识别性能。在两种介质中,RhB-NSal对Cu2+均具有很高的识别性能,仅Fe3+和Bi3+产生一定程度的干扰。RhB-NSal与Cu2+可逆性结合,形成摩尔比为1∶1的配合物,结合常数分别为6.72×104和4.23×104L/mol,对Cu2+的检测限分别为0.49和14.98μmol/L。在含水介质中,RhB-NSal识别Cu2+的灵敏度比在无水乙腈中稍低,但吸收光谱响应依然显著。硝基有助于提高RhB-NSal识别Cu2+的灵敏度,RhB-NSal有望成为Cu2+的荧光增强及可视型识别试剂。更多还原

【Abstract】 The sensing behaviors of a rhodamine derivative RhB-NSal bearing a —NO2group for Cu2 +in dry acetonitrile and aqueous acetate buffer media were investigated.In each medium,significant absorption and fluorescence enhancements accompanied by an instant color change were observed for RhB-NSal upon addition of Cu2 +.RhB-NSal reversibly bound with Cu2 +to form a 1∶1 stoichiometric complex with an association constant of 6.72 × 104 and 4.23 × 104 L /mol,respectively.RhB-NSal displayed a high selectivity for Cu2 +over other ions except that Fe3 +and Bi3 +ions induced a little interference.In dry acetonitrile,Cu2 +resulted in remarkable spectroscopic enhancements of RhB-NSal with a detection limit of 0.49 μmol /L for Cu2 +,exhibiting higher sensitivity than that of an analogue bearing no substituent on its phenol ring.In aqueous solution,RhB-NSal likewise displayed a higher selectivity but a lower sensitivity for Cu2 +than that in acetonitrile,with a detection limit of 14.98μmol/L,still more sensitive than RhB-Sal in absorption.By virtue of these properties,RhB-NSal could be used as a promising candidate for an"Off-On"fluorescent and colorimetric chemosensor for Cu2 +in different media.更多还原