title: TiO2-decorated graphene nanohybrids for fabricating an amperometric acetylcholinesterase biosensor.
abstract: This work describes a highly sensitive and rapid amperometric biosensor for organophosphate compounds (OPs) based on immobilization of acetylcholinesterase (AChE) on a novel TiO(2)-decorated graphene (TiO(2)-G) nanohybrid, which was constructed by in situ growth of TiO(2) nanoparticles (NPs) on the graphene sheet. The well-dispersed TiO(2) NPs eliminated the restacking of TiO(2)-G nanohybrids. Due to the integrating of TiO(2)-G nanohybrids, the as-prepared biosensor showed high affinity to acetylthiocholine (ATCl) with a Michaelis-Menten constant (K(m)) value of 0.22 mM, and rapid inhibition time (3 min). Further, based on the inhibition of OPs on the enzymatic activity of the immobilized AChE, and using carbaryl as a model compound, the inhibition of carbaryl was proportional to its concentration ranging from 0.001 to 0.015 and 0.015 to 2 μg mL(-1) with a detection limit of 0.3 ng mL(-1) (S/N = 3). The developed biosensor exhibited a good performance for organophosphate pesticide detection, including good reproducibility and acceptable stability, which provided a new and promising tool for the analysis of enzyme inhibitors.
authors: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, China. wangkun@ujs.edu.cn
authors: Kun
authors: K
authors: Wang
authors: He-Nan
authors: HN
authors: Li
authors: Jun
authors: J
authors: Wu
authors: Chang
authors: C
authors: Ju
authors: Jia-Jia
authors: JJ
authors: Yan
authors: Qian
authors: Q
authors: Liu
authors: Baijing
authors: B
authors: Qiu
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry / Q000378:metabolism*; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009943:Organophosphorus Compounds / Q000032:analysis; D010575:Pesticides / Q000032:analysis; D013499:Surface Properties; D013860:Thiocholine / Q000737:chemistry / Q000378:metabolism; D014025:Titanium / Q000737:chemistry*
chemical_list: D009943:Organophosphorus Compounds; D010575:Pesticides; C009495:titanium dioxide; D013860:Thiocholine; D006108:Graphite; D014025:Titanium; D000110:Acetylcholinesterase