State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P. R. China.
University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.
Anal Chem. 2020 Dec 15;92(24):16066-16071. doi: 10.1021/acs.analchem.0c03691. Epub 2020 Nov 19.
Integrating two kinds of fluorescent probes in one system to develop a ratiometric sensing platform is of prime importance for achieving an accurate assay. Inspired by the efficient overlapped spectrum of 2-aminoterephthalic acid (PTA-NH) and 2,3-diaminophenazine (DAP), a new sensitive ratiometric fluorescent sensor has been developed for Cu on the basis of in situ converting -phenylenediamine (OPD) into DAP through the catalysis of Cu. Here, the presence of Cu induced the emission of DAP, which acted as an energy acceptor to inhibit the emission of PTA-NH. This dual-emission reverse change ratiometric profile based on the inner-filter effect improved sensitivity and accuracy, and the highly sensitive determination of Cu with a detection limit of 1.7 nmol·L was obtained. The proposed sensing platform displayed the wide range of detection of Cu from 5 to 200 nmol·L by modulating the reaction time between Cu and OPD. Moreover, based on the specific interaction between glutathione (GSH) and Cu, this fluorescent sensor showed high response toward GSH in a range of 0.5-80 μmol·L with a detection limit of 0.16 μmol·L. The successful construction of this simple ratiometric sensing platform without the participation of enzymes provides a new route for the detection of small biological molecules that are closely related to human health.
在一个系统中集成两种荧光探针对于实现准确的分析至关重要。受 2-氨基对苯二甲酸（PTA-NH）和 2,3-二氨基吩嗪（DAP）高效重叠光谱的启发，基于 Cu 通过催化将 -苯二胺（OPD）原位转化为 DAP，开发了一种新的用于 Cu 的敏感比率荧光传感器。在这里，Cu 的存在诱导了 DAP 的发射，DAP 作为能量受体抑制了 PTA-NH 的发射。这种基于内滤效应的双发射反向变化比率特性提高了灵敏度和准确性，并且可以通过检测限为 1.7 nmol·L 的 Cu 获得高灵敏度的测定。通过调节 Cu 和 OPD 之间的反应时间，所提出的传感平台显示出从 5 到 200 nmol·L 的宽范围检测 Cu 的能力。此外，基于 GSH 和 Cu 之间的特异性相互作用，该荧光传感器在 0.5-80 μmol·L 的范围内对 GSH 表现出高响应，检测限为 0.16 μmol·L。这种简单的比率荧光传感平台的成功构建无需酶的参与，为检测与人类健康密切相关的小分子提供了一条新途径。
