title: Screen-printed biosensor based on the inhibition of the acetylcholinesterase activity for the determination of codeine.
abstract: The current paper presents the chronoamperometric determination of codeine using screen-printed carbon electrodes that incorporate tetrathiafulvalene in the matrix of the working electrode, as mediator, and cross-linked acetylcholinesterase. Applying a potential of +250 mV, a 1mM solution of acetylthiocholine in electrolyte solution pH 7 gives an oxidation signal due to the dimerization of its metabolite after the reaction with the enzyme. This electrochemical signal is decreased by consecutive additions of a solution of codeine, which allows the performance of curves of calibration for the validation of this electrochemical method, giving a reproducibility of 3.31% (n=6) and a capability of detection of 20 µM. This type of inhibition has been studied by means of a Lineweaver-Burk plot. Additionally, the developed biosensor was used for the determination of the quantity of codeine in pharmaceutical commercial tablets and urine samples.
authors.affiliation: Analytical Chemistry Department, Faculty of Sciences, University of Burgos, Plaza Misael Bañuelos s/n, 09001 Burgos, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Asturias-Arribas
authors.forename: M Asunción
authors.initials: MA
authors.lastname: Alonso-Lomillo
authors.forename: Olga
authors.initials: O
authors.lastname: Domínguez-Renedo
authors.forename: M Julia
authors.initials: MJ
authors.lastname: Arcos-Martínez
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002138:Calibration; D003061:Codeine / Q000032:analysis* / Q000652:urine; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D057075:Enzyme Assays / Q000379:methods; D004800:Enzymes, Immobilized / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D015203:Reproducibility of Results; D013607:Tablets / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D013607:Tablets; D000110:Acetylcholinesterase; D003061:Codeine