Abstract：
A bisalicylhydrazone based fluorescence probe, bisalicyladehyde benzoylhydrazone (BS-BH), has been designed to detect Al3+. It exhibited high sensitivity and selectivity towards Al3+ in methanol-water media in physiological condition. Large stokes shifts (∼122 nm) and over ∼1000-fold enhanced fluorescence intensity were observed, which was ascribed to the formation of the two relatively independent rigid extended π conjugated systems bridged by biphenyl group when binding with Al3+. A 1:2 binding ratio between BS-BH and Al3+ was shown by Job\'s plot. Based on the fluorescence titration data, the detection limit was down to 3.50 nM and the association constant was evaluated to be 1.12 × 109 M-2. The plausible fluorescence sensing mechanism of suppressed ESIPT, inhibited PET, activated CHEF and restricted C = N isomerization was confirmed by a variety of spectral experiments and DFT / TD-DFT calculations. The reversibility of recognition of Al3+ for probe BS-BH was validated by adding Na2-EDTA. In addition, the MTT assay showed the good biocompatibility of BS-BH and BS-BH could be used for imaging Al3+ in living cells.
摘要：
一种双酰腙基荧光探针,双醛苯甲酰腙（BS-BH），被设计用来检测Al3+。在生理条件下，它对甲醇-水介质中的Al3具有很高的灵敏度和选择性。观察到大的斯托克斯位移(~122nm)和超过~1000倍的荧光强度增强，这归因于与Al3结合时由联苯基团桥接的两个相对独立的刚性扩展π共轭体系的形成。在BS-BH和Al3+之间的1:2结合比通过Job's图显示。根据荧光滴定数据，检测限低至3.50nM,缔合常数评估为1.12×109M-2.抑制ESIPT的合理荧光传感机制，抑制PET，通过各种光谱实验和DFT/TD-DFT计算证实了活化的CHEF和限制的C=N异构化。通过添加Na2-EDTA验证了探针BS-BH识别Al3+的可逆性。此外,MTT实验表明BS-BH具有良好的生物相容性，BS-BH可用于活细胞中Al3+的成像。
