title: A new amperometric bienzymatic biosensor based on biocomposites for the determination of gluconic acid in wines.
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).
authors: Sensors and Biosensors Group, Department of Chemistry, Universitat Autònoma de Barcelona, Edifici Cn, 08193 Bellaterra, Barcelona, Spain.
authors: Xavier
authors: X
authors: Cetó
authors: Francisco
authors: F
authors: Céspedes
authors: Josefina
authors: J
authors: Capdevila
authors: Manel
authors: M
authors: del Valle
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004563:Electrochemistry; D005942:Gluconates / Q000032:analysis*; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D010734:Phosphogluconate Dehydrogenase / Q000378:metabolism*; D010766:Phosphorylation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D015203:Reproducibility of Results; D014920:Wine / Q000032:analysis*
chemical_list: D005942:Gluconates; D009249:NADP; D010734:Phosphogluconate Dehydrogenase; D017853:Phosphotransferases (Alcohol Group Acceptor); C020578:gluconokinase; C030691:gluconic acid