title: Oxidase-mimicking activity of ultrathin MnO2nanosheets in colorimetric assay of acetylcholinesterase activity.
abstract: In the present study, a novel colorimetric sensing platform was constructed for quantitative detection of acetylcholinesterase (AChE) activity and its inhibitor. Manganese dioxide (MnO2) nanosheets as an oxidase-mimicking nanomaterial could directly oxidize 3,3',5,5'-tetramethylbenzidine (TMB) into oxTMB without the need for horseradish peroxidase and H2O2. When AChE was introduced, acetylthiocholine could be catalytically hydrolyzed to produce thiocholine, which easily triggers the decomposition of MnO2nanosheets, causing the decrease of solution absorbance. Owing to the inhibition effect of organophosphorus pesticides, the enzymatic activity was suppressed, preventing the decomposition of MnO2and resulting in the increase of absorbance. Under optimal conditions, the colorimetric platform shows sensitive responses to AChE and paraoxon in the range of 0.1-15 mU mL-1and 0.001-0.1 μg mL-1, respectively. The detection limits of AChE and paraoxon reached 35 μU mL-1and 1.0 ng mL-1, respectively. Furthermore, the MnO2-TMB platform has been used to fabricate test strips for rapid and convenient visual detection of AChE and its inhibitor with highly promising performance.
authors.affiliation: School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164, USA. yuehe.lin@wsu.edu and Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Yan
authors.affiliation: School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164, USA. yuehe.lin@wsu.edu.
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
authors.affiliation: School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164, USA. yuehe.lin@wsu.edu.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Wu
authors.affiliation: School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164, USA. yuehe.lin@wsu.edu.
authors.forename: Chengzhou
authors.initials: C
authors.lastname: Zhu
authors.affiliation: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China.
authors.forename: Xingguang
authors.initials: X
authors.lastname: Su
authors.affiliation: School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164, USA. yuehe.lin@wsu.edu.
authors.forename: Dan
authors.initials: D
authors.lastname: Du
authors.affiliation: School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164, USA. yuehe.lin@wsu.edu.
authors.forename: Yuehe
authors.identifier: http://orcid.org/0000-0003-2152-675X
authors.initials: Y
authors.lastname: Lin
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis*; D000122:Acetylthiocholine; D002800:Cholinesterase Inhibitors / Q000032:analysis*; D003124:Colorimetry; D006861:Hydrogen Peroxide; D017895:Manganese Compounds; D049329:Nanostructures; D010087:Oxides; D010088:Oxidoreductases; D010261:Paraoxon / Q000032:analysis
chemical_list: D002800:Cholinesterase Inhibitors; D017895:Manganese Compounds; D010087:Oxides; D000122:Acetylthiocholine; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D000110:Acetylcholinesterase; D010261:Paraoxon; C016552:manganese dioxide