Abstract: A polymeric membrane-based ion-selective electrode (ISE) for the determination of l-ascorbic acid (l-AA) was developed. The sensor was fabricated by modifying glassy carbon electrodes with molecularly imprinted polypyrrole (PPy) synthesized by electropolymerization of the monomer in the presence of ascorbate. A comparison between the non-imprinted modified electrode (PPy-NIP) and the molecularly imprinted polymer (PPy-MIP) is reported. The molecularly imprinted polymer improves the performances of the sensor, especially if the PPy film has been submitted to an oxidation treatment. The PPy-MIPox electrode shows near-Nernstian response (approx. -57 mV/decade) to the ascorbate over the concentration range between 5 x 10-6 M and 2 x 10-3 M and it can be used for more than 3 weeks without any considerable change in the measured response. The potentiometric sensor has been successfully applied to the determination of ascorbate in food and pharmaceutical samples (recoveries of about 100%)
Template and target information: l-ascorbic acid, l-AA
Author keywords: ISE, Potentiometry, polypyrrole, molecular imprinted polymers, ascorbic acid

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