RESUMEN
A low-cost and sensitive amperometric biosensor was developed for the determination of α-amylase activity. The biosensor was constructed by immobilizing glucose oxidase-gelatin via glutaraldehyde on the Au electrode surface. Measurements were carried out chronoamperometrically at -0.7 V. Several parameters such as glucose oxidase activity, gelatin amount, and glutaraldehyde percentage for cross-linking were optimized. Optimum pH, optimum temperature, repeatability, and storage stabilities of the biosensor were identified. Under the optimum experimental conditions, a linear calibration curve was obtained for α-amylase between 0.819 and 13.110 U/ml. Sample analyses were carried out by detecting α-amylase activities in baker's yeast samples.
Asunto(s)
Técnicas Biosensibles/métodos , Electroquímica/métodos , Oro/química , alfa-Amilasas/metabolismo , Aspergillus niger/enzimología , Bacillus subtilis/enzimología , Electrodos , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Glucosa/metabolismo , Glucosa Oxidasa/química , Glucosa Oxidasa/metabolismo , Glutaral/metabolismo , Concentración de Iones de Hidrógeno , Hidrólisis , Modelos Lineales , Oxígeno/metabolismo , Almidón/metabolismo , Propiedades de Superficie , TemperaturaRESUMEN
A glucose oxidase-based biosensor was developed for the determination of α-amylase activity. The determination method is based on monitoring the decrease in dissolved oxygen concentration related to the starch concentration, for which starch gives a reaction with α-amylase. Optimization parameters, including glucose oxidase amount, gelatin amount, and glutaraldehyde percentage for cross-linking, were investigated. The effects of pH, buffer system, and temperature on the biosensor system were also investigated. The biosensor had a linear relation to α-amylase activity and good measurement correlation between 0.66 and 9.83 U/ml. In sample analysis studies, α-amylase activity in baker's yeast was determined by the biosensor.