A new amperometric bienzymatic biosensor based on biocomposites for the determination of gluconic acid in wines

Talanta. 2011 Aug 15;85(2):1207-12. doi: 10.1016/j.talanta.2011.05.047. Epub 2011 May 30.

Abstract

A new amperometric bienzymatic biosensor for gluconic acid based on the coimmobilization of gluconokinase (EC 2.7.1.12) and phosphogluconate dehydrogenase (EC 1.1.1.44) by polysulfone membrane entrapment onto the surface of a graphite-epoxy composite is reported. This biosensor represents an alternative to gluconate dehydrogenase (EC 1.1.99.3) based methods, which is no longer commercially available. Measurements were done at an applied potential of +0.800 V, room temperature and phosphate buffer pH 7.50; obtaining a linear response range for gluconic acid extended from 7.0 × 10(-6) to 2.5 × 10(-4)M. Constructed biosensors showed good reproducibility for calibrations using different electrodes (RSD of 1.74%). Finally, biosensor was applied to real wine samples, and the results obtained were validated by comparison with those provided by a reference laboratory. Good correlation was found when the biosensor results were plotted vs. the reference values (slope=1.03 ± 0.04, intercept=0.01 ± 0.02, r(2)=0.995).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosensing Techniques / methods*
  • Electrochemistry
  • Gluconates / analysis*
  • NADP / metabolism
  • Oxidation-Reduction
  • Phosphogluconate Dehydrogenase / metabolism*
  • Phosphorylation
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*
  • Reproducibility of Results
  • Wine / analysis*

Substances

  • Gluconates
  • NADP
  • Phosphogluconate Dehydrogenase
  • Phosphotransferases (Alcohol Group Acceptor)
  • gluconokinase
  • gluconic acid