Fletcher James T, Bruck Brent S
Department of Chemistry, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA.
Sens Actuators B Chem. 2015 Feb 1;207(Pt A):843-848. doi: 10.1016/j.snb.2014.10.116.
A dicarboxylated ethynylarene was shown to behave as a fluorescent chemosensor for millimolar concentrations of polyamines when mixed with Cd(II), Pb(II) or Zn(II) ions at micromolar concentrations. A bathochromic shift and intensification of fluorescence emission was observed with increasing amounts of metal ion in the presence of aqueous polyamines buffered at pH = 7.6. Such perturbations manifested as 'turn-on' signals from a ratiometric comparison of emission intensities at 390 nm versus 340 nm. Using Pb(II) as the metal mediator, spermine was selectively detected as a 40-fold signal enhancement relative to spermidine, putrescine, cadaverine and several other non-biogenic diamines. Evaluation of additional triamine and tetraamine analytes showed the influence that amine group quantity and spacing had on signal generation. By increasing the ratio of Pb(II) relative to ethynylarene, the detection limit for spermine was successfully lowered to a 25 micromolar level. Noncovalent association between ethynylarene, metal ion and polyamine are believed to promote the observed spectroscopic changes. This study exploits the subtle impact that polyamine structural identity has on transition metal chelation to define a new approach towards polyamine chemosensor development.
当与微摩尔浓度的镉（II）、铅（II）或锌（II）离子混合时，一种二羧酸乙炔基芳烃被证明可作为毫摩尔浓度多胺的荧光化学传感器。在pH = 7.6的水性多胺存在下，随着金属离子量的增加，观察到荧光发射的红移和增强。这种扰动表现为390 nm与340 nm发射强度的比率比较产生的“开启”信号。以铅（II）作为金属介质，相对于亚精胺、腐胺、尸胺和其他几种非生物源二胺，精胺被选择性地检测为信号增强40倍。对其他三胺和四胺分析物的评估显示了胺基数量和间距对信号产生的影响。通过增加铅（II）相对于乙炔基芳烃的比例，精胺的检测限成功降低到25微摩尔水平。乙炔基芳烃、金属离子和多胺之间的非共价缔合被认为促进了观察到的光谱变化。本研究利用多胺结构特征对过渡金属螯合的微妙影响，定义了一种开发多胺化学传感器的新方法。
