Direct Electrochemistry of Laccase Immobilized on Au Nanoparticles Encapsulated-Dendrimer Bonded Conducting Polymer: Application for a Catechin Sensor
- 8 October 2008
- journal article
- research article
- Published by American Chemical Society (ACS) in Analytical Chemistry
- Vol. 80 (21), 8020-8027
- https://doi.org/10.1021/ac801033s
Abstract
The direct electrochemistry of laccase was promoted by Au nanoparticle (AuNP)-encapsulated dendrimers (Den), which was applied for the detection of catechin. To increase the electrical properties, AuNPs were captured in the interiors of the dendrimer (Den-AuNPs) as opposed to attachment at the periphery of dendrimer. To prepare Den-AuNPs, the Au(III) ions were first coordinated in the interior of dendrimer with nitrogen ligands and then reduced to form AuNPs. The size of AuNPs encapsulated within the interior of the dendrimer was determined to be 1.7 ± 0.4 nm. AuNPs-encapsulated dendrimers were then used to covalently immobilize laccase (PDATT/ Den(AuNPs)/laccase) through the formation of amide bonds between carboxylic acid groups of the dendrimer and the amine groups of laccase. Each layer of the PDATT/Den(AuNPs)/laccase probe was characterized using CV, EIS, QCM, XPS, SEM, and TEM. The PDATT/Den(AuNPs)/laccase probe displayed a well-defined direct electron-transfer (DET) process of laccase. The quasi-reversible redox peak of the Cu redox center of the laccase molecule was observed at −0.03/+0.13 V vs Ag/AgCl, and the electron-transfer rate constant was determined to be 1.28 s−1. A catechin biosensor based on the electrocatalytic process by direct electrochemistry of laccase was developed. The linear range and the detection limit in the catechin analysis were determined to be 0.1−10 and 0.05 ± 0.003 μM, respectively. Interference effects from various phenolic and polyphenolic compounds were also studied, and the general applicability of the biosensor was evaluated by selective analysis of real samples of catechin.Keywords
This publication has 33 references indexed in Scilit:
- Biosensor for the determination of phenols based on Cross-Linked Enzyme Crystals (CLEC) of laccaseBiosensors and Bioelectronics, 2005
- Electrochemical Characterization of Purified Rhus vernicifera Laccase: Voltammetric Evidence for a Sequential Four-Electron TransferBiochemistry, 2003
- Determination of Tea Components with Antioxidant ActivityJournal of Agricultural and Food Chemistry, 2003
- Separation and Identification of Twelve Catechins in Tea Using Liquid Chromatography/Atmospheric Pressure Chemical Ionization-Mass SpectrometryAnalytical Chemistry, 2000
- Determination of tea catechinsJournal of Chromatography A, 2000
- Direct electron transfer between heme-containing enzymes and electrodes as basis for third generation biosensorsAnalytica Chimica Acta, 1999
- Unmediated heterogeneous electron transfer reaction of ascorbate oxidase and laccase at a gold electrodeBiochemical Journal, 1998
- Enzyme Bioelectrochemistry in Cast Biomembrane-Like FilmsAccounts of Chemical Research, 1998
- Method To Assay the Concentrations of Phenolic Constituents of Biological Interest in WinesAnalytical Chemistry, 1996
- Analysis of tea flavanols by gas chromatography of their trimethylsilyl derivativesAnalytical Chemistry, 1969