title: Selective and sensitive detection of acetylcholinesterase activity using denatured protein-protected gold nanoclusters as a label-free probe.
abstract: Based on the fluorescence quenching of novel denatured protein-protected gold nanoclusters, a label-free detection method of acetylcholinesterase (AChE) activity has been developed. Using denatured bovine serum albumin (dBSA), in which 35 cysteine residues can interact polyvalently with Au nanoclusters (AuNCs) as a stabilizing agent, water-soluble and stable fluorescent gold nanoclusters were synthesized. The fluorescence of the AuNCs was quenched by thiocholine that was produced from the AChE hydrolysis of S-acetylthiocholine iodide (ACTI) to detect the AChE activity. The linear range of the method was 0.005-0.15 U mL(-1). The limit of detection (LOD) was 0.02 mU mL(-1). Other enzymes and metal ions, i.e., GPT, γ-GT, GOx, K(+), Ca(2+) and Na(+), showed minimal interference. Using the fluorescence probe, satisfactory results for the detection of the AChE activity in human serum were obtained.
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Hunan Normal University, Changsha 410081, China. lehuixiao@gmail.com dr-chenpo@vip.sina.com.
authors.forename: Hongchang
authors.initials: H
authors.lastname: Li
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Guo
authors.forename: Lehui
authors.initials: L
authors.lastname: Xiao
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis* / Q000097:blood; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D004789:Enzyme Activation / Q000502:physiology; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D011489:Protein Denaturation
chemical_list: D006046:Gold; D000110:Acetylcholinesterase