title: Highly sensitive GQDs-MnO2based assay with turn-on fluorescence for monitoring cerebrospinal acetylcholinesterase fluctuation: A biomarker for organophosphorus pesticides poisoning and management.
abstract: In this study, we demonstrated an assay with turn-on fluorescence for monitoring cerebrospinal acetylcholinesterase (AChE) fluctuation as a biomarker for organophosphorus pesticides (OPs) poisoning and management based on single layer MnO2nanosheets with graphene quantum dots (GQDs) as signal readout. Initially, the fluorescence of GQDs was quenched by MnO2nanosheets mainly due to the inner filter effect (IFE). However, with the presence of reductive thiocholine (TCh), the enzymatic product, hydrolyzed from acetylthiocholine (ATCh) by AChE, the redox reaction between MnO2and TCh occurred, leading to the destruction of the MnO2nanosheets, and thereby IFE was diminished gradually. As a consequence, the turn-on fluorescence of GQDs with the changes in the spectrum of the dispersion constituted a new mechanism for sensing of cerebrospinal AChE. With the method developed here, we could monitor cerebrospinal AChE fluctuation of rats exposed to OPs before and after therapy, and could thereby open up the pathway to a new sensing platform for better understanding the mechanism of brain dysfunctions associate with OPs poisoning.
authors.affiliation: School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Deng
authors.affiliation: School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China.
authors.forename: Dingkun
authors.initials: D
authors.lastname: Lu
authors.affiliation: School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China.
authors.forename: Guoyue
authors.initials: G
authors.lastname: Shi
authors.affiliation: School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China. Electronic address: tszhou@des.ecnu.edu.cn.
authors.forename: Tianshu
authors.initials: T
authors.lastname: Zhou
mesh_terms: D000110:Acetylcholinesterase / Q000134:cerebrospinal fluid*; D000818:Animals; D001681:Biological Assay; D015415:Biomarkers / Q000134:cerebrospinal fluid; D006108:Graphite / Q000737:chemistry*; D008297:Male; D017895:Manganese Compounds / Q000737:chemistry*; D057145:Nanoshells / Q000737:chemistry; D062025:Organophosphate Poisoning / Q000134:cerebrospinal fluid* / Q000628:therapy; D010087:Oxides / Q000737:chemistry*; D010575:Pesticides / Q000506:poisoning; D045663:Quantum Dots / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D015415:Biomarkers; D017895:Manganese Compounds; D010087:Oxides; D010575:Pesticides; D006108:Graphite; D000110:Acetylcholinesterase; C016552:manganese dioxide
keywords: Cerebrospinal acetylcholinesterase; GQDs-MnO(2); Organophosphorus pesticides; Turn-on fluorescent assay