An Ethanol Biosensor Based on Simple Immobilization of Alcohol Dehydrogenase on Fe3O4@Au Nanoparticles |
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| Authors: | Anchalee Samphao Kanjana Kunpatee Sanchai Prayoonpokarach Jatuporn Wittayakun Ľubomír Švorc Dalibor M. Stankovic Kristina Zagar Miran Ceh Kurt Kalcher |
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| Affiliation: | 1. Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190 Thailand, Tel: +66?85?055?1717 Fax: +66?45?288?400;2. Material Chemistry Research Group, School of Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, 30000 Thailand;3. Institute of Analytical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, Bratislava SK‐812 37, Slovak Republic;4. Department of Analytical Chemistry, Innovation Center of the Faculty of Chemistry, University of Belgrade, Studentski trg 12–16, Belgrade 11000, Serbia;5. Department for Nanostructured Materials, Jozef Stefan Institute, 1000 Ljubljana, Slovenia;6. Institute of Chemistry‐Analytical Chemistry, Karl‐Franzens‐University, A‐8010 Graz, Austria |
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| Abstract: | An ethanol biosensor based on alcohol dehydrogenase (ADH) attached to Au seeds decorated on magnetic nanoparticles (Fe3O4@Au NPs) is presented. ADH was immobilized on Fe3O4@Au NPs, which were subsequently fixed by a magnet on a carbon paste electrode modified with 5 % (m : m) MnO2. Optimum conditions for the amperometric determination of ethanol with the biosensor were as follows: working potential +0.1 V (vs. Ag/AgCl); supporting electrolyte: 0.1 M phosphate buffer solution at pH 6.8 containing 0.25 mM of the coenzyme (NAD+); working electrode: carbon paste with magnetically attached Fe3O4@Au NPs (0.012 mg ? cm?2 electrode area) with immobilized alcohol dehydrogenase (120 units per cm2 of electrode area). Linearity between signal and concentration was found for the range from 0.1 to 2.0 M ethanol (r2=0.995) with a detection limit of 0.07 M, a sensitivity of 0.02 µA ? mM?1 ? cm?2, a reproducibility of 4.0 % RSD, and a repeatability of 2.7 % RSD. The results for the determination of ethanol in alcoholic beverages showed good agreement with gas chromatography (GC) with recovery of 96.0 – 108.8 %. |
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| Keywords: | Magnetic‐gold nanoparticles ethanol biosensor carbon paste electrode ethanol determination alcohol dehydrogenase |
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