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

作者：Ceto Xavier; Cespedes Francisco; Capdevila Josefina; del Valle Mane^*

来源：Talanta, 2011, 85(2): 1207-1212.

DOI：10.1016/j.talanta.2011.05.047

• Gluconic acid
• Amperometric biosensor
• Wine
• Bienzymatic
• Gluconokinase

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 x 10(-6) to 2.5 x 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).

• 出版日期2011-8-15