Ascorbic Acid Determination by an Amperometric Ascorbate Oxidase-based Biosensor
نویسنده
چکیده
The aim of this work is to develop a method for ascorbic acid determination in some fruit juices, by using an ascorbate oxidase-based amperometric enzyme electrode. The enzyme was immobilized on a nylon (Biodyne A) membrane by glutaraldehyde linking. The enzyme-membrane was consecutively attached to the polyethylene membrane of a Clark oxygen electrode, which functioned as transducer. The analytical characteristics of the biosensor (linear range, sensitivity, selectivity, response time, stability) were investigated, as well as the influence of the enzyme loading. The value of the current intensity was monitored, as a function of time, for different ascorbic acid concentrations. The obtained calibration graph was linear within the range 0.10-0.55 mM. The optimum biosensor response was obtained for an ascorbate oxidase amount immobilized on the membrane of 100 U. The values of vitamin C content of the analysed fruit juices ranged between 0.48 and 1.98 mM.
منابع مشابه
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