title: Amperometric biosensor based on tyrosinase-conjugated polysaccharide hybrid film: selective determination of nanomolar neurotransmitters metabolite of 3,4-dihydroxyphenylacetic acid (DOPAC) in biological fluid.
abstract: The amperometric detection of neurotransmitters metabolite of 3,4-dihydroxyphenylacetic acid (DOPAC) was achieved at a tyrosinase-chitosan composite film-modified glassy carbon (GC) electrode. The optimal conditions for the preparation of the biosensor were established. This bio-composite film was characterized by scanning electron microscopy (SEM) and Fourier transformed infrared (FT-IR) spectra, suggesting that chitosan covalently connected to chitosan chains. Electrochemical characterization of the bio-hybrid membrane-covered electrodes were also performed in 0.05 M phosphate buffer solution (pH 6.52) containing neurotransmitters or their derivatives by using cyclic voltammetry (CV), linear sweep voltammetry (LSV), square wave voltammetry (SWV) and amperometry. This simply-prepared protein-polysaccharide hybrid film provides a microenvironment friendly for enzyme loading. The sensor was operated at -0.15 V with a short response time. The current linearly increased with the increasing concentration of DOPAC over the concentration of 6 nM-0.2 mM. The lower detection limit for DOPAC is 3 nM (S/N=3). The sensitivity of the sensor is 40 microA mM(-1). A physiological level of neurotransmitters and their derivatives including dopamine, l-dopa, adrenaline, noradrenaline and homovanillic acid as well as ascorbic acid, uric acid and acetaminophen do not affect the determination of DOPAC.
authors.affiliation: Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Umezono 1-1-1, Tsukuba 305-8568, Japan.
authors.forename: Aihua
authors.initials: A
authors.lastname: Liu
authors.forename: Itaru
authors.initials: I
authors.lastname: Honma
authors.forename: Haoshen
authors.initials: H
authors.lastname: Zhou
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000032:analysis* / Q000378:metabolism*; D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D001826:Body Fluids / Q000378:metabolism*; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008567:Membranes, Artificial; D008832:Microchemistry / Q000295:instrumentation / Q000379:methods; D008839:Microelectrodes; D014442:Monophenol Monooxygenase / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D018377:Neurotransmitter Agents / Q000032:analysis* / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D018377:Neurotransmitter Agents; D011134:Polysaccharides; D015102:3,4-Dihydroxyphenylacetic Acid; D014442:Monophenol Monooxygenase