A new amperometric carbon paste enzyme electrode for ethanol determination


Koyuncu D., ERDEN P. E. , Pekyardimci S., Kilic E.

ANALYTICAL LETTERS, vol.40, no.10, pp.1904-1922, 2007 (Peer-Reviewed Journal) identifier

  • Publication Type: Article / Article
  • Volume: 40 Issue: 10
  • Publication Date: 2007
  • Doi Number: 10.1080/00032710701384691
  • Journal Name: ANALYTICAL LETTERS
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.1904-1922
  • Keywords: alcohol dehydrogenase, amperometry, enzyme electrode, carbon paste, ethanol, poly(vinylferrocene), ALCOHOL-DEHYDROGENASE, ELECTROCATALYTIC OXIDATION, NICOTINAMIDE COENZYMES, MICROBIAL BIOSENSOR, NADH, SENSOR, WINES, SYSTEMS, LIQUID, BEER

Abstract

In this study, a new amperometric carbon paste enzyme electrode for determination of ethanol was developed. The carbon paste was prepared by mixing alcohol dehydrogenase, its coenzyme nicotinamide adenine dinucleotide (oxidized form, NAD(+)), poly(vinylferrocene) (PVF) that was used as a mediator, graphite powder and paraffin oil, then the paste was placed into cavity of a glass electrode body. Determination of ethanol was performed by oxidation of nicotinamide adenine dinucleotide (reduced form, NADH) generated enzymatically at +0.7 V. The effects of enzyme, coenzyme and PVF amounts; pH; buffer concentration and temperature were investigated. The linear working range of the enzyme electrode was 4.0 x 10(-4) - 4.5 x 10(-3) M, determination limit was 3.9 x 10(-4) M and response time was 50s. The optimum pH, buffer concentration, temperature, and amounts of enzyme, NAD(+) and PVF for enzyme electrode were found to be 8.5, 0.10 M, 37 degrees C, 2.0, 6.0, and 12.0 mg, respectively. The storage stability of enzyme electrode at +4 degrees C was 7 days. Enzyme electrode was used for determination of ethanol in two different wine samples and results were in good agreement with those obtained by gas chromatography.