title: Preparation of a highly sensitive enzyme electrode using gold nanoparticles for measurement of pesticides at the ppt level.
abstract: A highly sensitive enzyme electrode was prepared based on gold nanoparticles for measurement of pesticides. Gold nanoparticles of 25-30 nm were synthesized on a glassy carbon electrode by double-pulse technique while the coverage was controlled by applied potential and time. The gold nanoparticles were modified to form a self-assembled monolayer, followed by covalent binding of tyrosinase. The TYR-AuNP-GC electrode was compared with bare GC, AuNP-GC, and modified AuNP-GC and TYR-Au (plate type) electrodes in terms of cyclic voltammetry. The voltammograms well represent the sensitivity of enzymatic oxidation of catechol, substrates for the enzyme activity. The prepared electrode integrated into a continuous flow system and was tested to detect pesticides, such as 2,4-D, atrazine, and ziram. Under the optimized conditions of the flow system, the electrode performed reasonably according to the inhibition mechanism in the concentration range of 0.001-0.5 ng mL(-1). The enhanced performance was attributed to the favored microenvironment for the enzyme activity provided by SAM on gold nanoparticles.
authors.affiliation: Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 261 Cheomdan-Gwagiro, Buk-gu, Gwangju 500-712, South Korea.
authors.forename: Gha-Young
authors.initials: GY
authors.lastname: Kim
authors.forename: Joonmok
authors.initials: J
authors.lastname: Shim
authors.forename: Min-Su
authors.initials: MS
authors.lastname: Kang
authors.forename: Seung-Hyeon
authors.initials: SH
authors.lastname: Moon
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000032:analysis; D015097:3-Mercaptopropionic Acid / Q000737:chemistry; D001280:Atrazine / Q000032:analysis; D015374:Biosensing Techniques; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles; D014442:Monophenol Monooxygenase / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis*; D012680:Sensitivity and Specificity; D014867:Water / Q000032:analysis; D015039:Ziram / Q000032:analysis
chemical_list: D010575:Pesticides; D014867:Water; D015084:2,4-Dichlorophenoxyacetic Acid; D015039:Ziram; D006046:Gold; D015097:3-Mercaptopropionic Acid; D014442:Monophenol Monooxygenase; D001280:Atrazine