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Preparation of a highly sensitive enzyme electrode using gold nanoparticles for measurement of pesticides at the ppt level

2008; Royal Society of Chemistry; Volume: 10; Issue: 5 Linguagem: Inglês

10.1039/b800553b

1464-0333

Gha-Young Kim, Joonmok Shim, Minsu Kang, Seung‐Hyeon Moon,

Biotin and Related Studies

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.