Parkesh Raman, Clive Lee T, Gunnlaugsson Thorfinnur
School of Chemistry, Centre for Synthesis and Chemical Biology (CSCB), Trinity College Dublin, Dublin 2, Ireland.
Org Biomol Chem. 2007 Jan 21;5(2):310-7. doi: 10.1039/b614529a. Epub 2006 Nov 16.
The design and synthesis of two novel fluorescent sensors based on the photoinduced electron transfer (PET) concept, and , for the detection of zinc under competitive media is described. These sensors are based on the 4-amino-1,8-naphthalimide fluorophore, which has an absorption band centred at 450 nm and emits in the green with lambda(max) approximately 550 nm. By functionalizing the chromophore with a simple benzyl or ethyl-aryl based iminodiacetate receptor at the 4-position, both high selectivity and sensitivity were achieved for the sensing of Zn(II) over other competitive transition and Group I and II metal ions. These sensors were also shown to be pH independent, with a pKa of 2.3 being determined for , which allows these to be used in highly competitive pH media. Upon sensing of Zn(II) the fluorescence emission spectrum is 'switched on' demonstrating the suppression of PET from the receptor to the fluorophore. For , the sensing of Zn(II) was achieved with Kd = 4 nM when measured in pH 7.4 buffered solution, in the presence of 1.1 mM of EGTA.
本文描述了基于光诱导电子转移（PET）概念设计并合成的两种新型荧光传感器，用于在竞争介质中检测锌。这些传感器基于4-氨基-1,8-萘二甲酰亚胺荧光团，其吸收带中心位于450 nm，发射绿光，最大发射波长约为550 nm。通过在4-位用简单的苄基或基于乙基-芳基的亚氨基二乙酸受体对发色团进行功能化，实现了对锌（II）相对于其他竞争性过渡金属以及第I和II族金属离子的高选择性和高灵敏度检测。这些传感器还显示出与pH无关，测得的pKa为2.3，这使得它们能够在竞争激烈的pH介质中使用。在检测到锌（II）时，荧光发射光谱“开启”，表明从受体到荧光团的PET受到抑制。对于，在pH 7.4缓冲溶液中、存在1.1 mM乙二胺四乙酸（EGTA）的情况下进行测量时，检测锌（II）的解离常数（Kd）为4 nM。
