Open AccessThe Synthesis of a Coumarin Carbohydrazide Dinuclear Copper Complex Based Fluorescence Probe and Its Detection of Thiols
Author(s) -
Guangjie He,
Jing Li,
Lu Yang,
Chenliang Hou,
Tianjun Ni,
Zhaohui Yang,
Xiangyang Qian,
Changzheng Li
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0148026
Subject(s) - fluorescence , chemistry , cysteine , copper , thiol , coumarin , glutathione , carbohydrazide , photochemistry , molecule , quenching (fluorescence) , medicinal chemistry , organic chemistry , enzyme , physics , quantum mechanics
Small-molecule thiols, such as cysteine (CYS) and glutathione (GSH), are essential for maintaining the cellular redox environment and play important roles in regulating various cellular physiological functions. A fluorescence probe (compound 1-Cu 2+ ) for thiols based on coumarin carbohydrazide dinuclear copper complex was developed. Compound 1 was synthesized from the reaction of 7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide with 4-tert-butyl-2,6- diformylphenol. Accordingly, the copper complex (compound 1-Cu 2+ ) was prepared by mixing compound 1 with 2 equivalents copper ions. Compound 1 had strong fluorescence while compound 1-Cu 2+ hardly possessed fluorescence owing to the quenching nature of paramagnetism Cu 2+ to the fluorescence molecule excited state. However, the fluorescence intensity of compound 1-Cu 2+ was increased dramatically after the addition of thiol-containing amino acids, but not the other non-sulfhydryl amino acids. UV-vis absorption and fluorescence spectra indicated that compound 1-Cu 2+ had good selectivity and sensitivity for thiols such as glutathione in CH 3 CN:H 2 O (3:2, v/v) PBS solution. The fluorescence imaging experiments implied that compound 1-Cu 2+ has potential application in thiol-containing amino acids detection in living cells.