(AGENPARL) – LONDON (UNITED KINGDOM), lun 28 settembre 2020
This work demonstrates a new strategy for sensing of cerebrospinal acetylcholinesterase (AChE) as a cholinergic biomarker for brain dysfunction based on graphene quantum dots (GQDs) functionalized lanthanide infinite coordination polymer (Ln-ICP) nanoparticles. The ICPs used in this work are comprised of two components: one is the supramolecular Ln-ICP host formed by the coordination between the ligand GMP and central metal ion Tb3+; and the other is the guest GQDs with the abundant functional groups, which is utilized as the antenna ligand to further sensitize the fluorescence of Tb/GMP. Upon being excited at 300 nm, the obtained GQDs@Tb/GMP ICP nanoparticles exhibits the enhanced green fluoresence of Tb/GMP. With the addition of Cu2+, the competitive coordination between Cu2+ and GQDs weakens the antenna effect, leading to the decrease of the fluorescence of GQDs@Tb/GMP ICPs. However, with the presence of thiocholine (TCh), a thiol-containing compound hydrolyzed from acetylthiocholine (ATCh) by AChE, the stronger coordination interaction between Cu2+ and TCh occurrs, resulting in the restoration of the fluorescence of GQDs@Tb/GMP ICPs. With the method established here, the cerebrospinal AChE fluctuation of rats with acute organophosphorus pesticides (OPs) poisoning or chronic Alzheimer’s disease (AD) could be monitored. This study essentially provides a novel approach to realize direct monitoring of the biomarker for brain dysfunction by regulating the competitive coordination interaction reversibly, which is of critical importance in early diagnosing and therapy of brain diseases.
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