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 × 10−6M and 2 × 10−3M 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%).
A novel potentiometric sensor for l-ascorbic acid based on molecularly imprinted polypyrrole / D.Tonelli; B. Ballarin; L. Guadagnini; A. Mignani; E.Scavetta. - In: ELECTROCHIMICA ACTA. - ISSN 0013-4686. - STAMPA. - 56:(2011), pp. 7149-7154. [10.1016/j.electacta.2011.05.076]
A novel potentiometric sensor for l-ascorbic acid based on molecularly imprinted polypyrrole
TONELLI, DOMENICA;BALLARIN, BARBARA;GUADAGNINI, LORELLA;MIGNANI, ADRIANA;SCAVETTA, ERIKA
2011
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 × 10−6M and 2 × 10−3M 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%).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
