title: Amperometric choline biosensor based on multiwalled carbon nanotubes/zirconium oxide nanoparticles electrodeposited on glassy carbon electrode.
abstract: A bienzymatic choline biosensor was constructed by coimmobilizing acetylcholinesterase (AChE) and choline oxidase (ChO) onto nanocomposite of carboxylated multiwalled carbon nanotubes (c-MWCNTs) and zirconium oxide nanoparticles (ZrO(2)NPs) electrodeposited on the surface of a glassy carbon electrode (GCE) and using it (AChE-ChO/c-MWCNT/ZrO(2)NPs/GCE) as working electrode, Ag/AgCl as reference electrode, and Pt wire as auxiliary electrode connected through a potentiostat. The enzyme electrode was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and cyclic voltammetry (CV) studies, optimized, and evaluated. The biosensor exhibited optimum response within 4 s at +0.2V, pH 7.4, and 25 °C. The detection limit and working range of the biosensor were 0.01 μM and 0.05 to 200 μM, respectively. The half-life of the enzyme electrode was 60 days at 4 °C. The serum choline level, as measured by the biosensor, was 9.0 to 12.8 μmol/L (with a mean of 10.81 μmol/L) in apparently healthy persons and 5.0 to 8.4 μmol/L (with a mean of 6.53 μmol/L) in persons suffering from Alzheimer's disease. The enzyme electrode was unaffected by a number of serum substances.
authors.affiliation: Department of Food Sciences, School of Chemical Sciences, University of Auckland, Auckland, New Zealand.
authors.forename: S
authors.initials: S
authors.lastname: Pundir
authors.forename: N
authors.initials: N
authors.lastname: Chauhan
authors.forename: J
authors.initials: J
authors.lastname: Narang
authors.forename: C S
authors.initials: CS
authors.lastname: Pundir
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry*; D000293:Adolescent; D000328:Adult; D000429:Alcohol Oxidoreductases / Q000737:chemistry*; D000544:Alzheimer Disease / Q000097:blood*; D015374:Biosensing Techniques; D002648:Child; D002675:Child, Preschool; D002794:Choline / Q000097:blood*; D055664:Electrochemical Techniques; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D005260:Female; D006801:Humans; D007223:Infant; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D053758:Nanoparticles / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D015040:Zirconium; D000429:Alcohol Oxidoreductases; C019888:choline oxidase; D000110:Acetylcholinesterase; D002794:Choline; C028541:zirconium oxide