title: Ionic liquid-functionalized graphene for fabricating an amperometric acetylcholinesterase biosensor.
abstract: This work reports a sensitive amperometric biosensor for organophosphate pesticides (OPs) fabricated by modifying a glassy carbon electrode with acetylcholinesterase (AChE) immobilized on ionic liquid-functionalized graphene (IL-G). The functionalized graphene sheets had good dispersibility and long-term stability in various solvents. The as-prepared biosensor showed high affinity to acetylthiocholine (ATCl) with a Michaelis-Menten constant (K(m)) value of 0.77 mM. Furthermore, based on the inhibition by OPs of 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 0.0025 to 0.48 and 0.48 to 1.42 μg mL(-1) with a detection limit of 0.8 ng mL(-1) (S/N = 3). The developed biosensor exhibited a good performance for OPs detection, including good reproducibility and acceptable stability, which provided a new and promising tool for the analysis of enzyme inhibitors.
authors.affiliation: Institute of Molecular Science, Chemical Biology and Molecular Engineering, Laboratory of Education Ministry, Shanxi University, Taiyuan 030006, P.R. China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Li
authors.forename: Gaoyi
authors.initials: G
authors.lastname: Han
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D015374:Biosensing Techniques; D006108:Graphite / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning
chemical_list: D006108:Graphite; D000110:Acetylcholinesterase