Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XVII
Written by Florentina HUTANU, Emilia OCNARU, Melania-Liliana ARSENE, Mihaela BADEA-DONI
The development of a highly selective and sensitive sensor for H2O2 in beverages such as natural juices, is described in this work. The sensor is based on the deposition of Prussian Blue (PB) onto screen-printed carbon electrodes (SPCEs) followed by the electropolymerization of a non-conducting film. Several procedures for PB deposition on the SPE electrodes were tested: electrochemical deposition (potentiostatic, cyclic voltammetry) and chemical deposition. The electrochemical and analytical properties of the SPCE/PB sensors had been evaluated and the potentiostatic method for PB deposition was selected for the further development of the H2O2 sensor. In order to develop a robust sensor for H2O2 determination in samples with complex matrix, we covered the PB layer with an electropolymerized nonconducting film with a high permselectivity for H2O2. This film is a copolymer based on 2,6-DHN (2,6- dihydroxynaphtalene) and APEA (2-(4-aminophenyl)-ethylamine). The SPCE/PB/copolymer sensor demonstrated improved stability in operational conditions and excellent interference rejection properties. This sensor may be successfully applied on-field, using a portable potentiostat-galvanostat and the chronoamperometry technique, as well as in a laboratory bench flow injection analysis system with amperometric detection. The developed sensor was able to measure H2O2 in the linear range 1 M – 500 M (R=0.9989), with a detection limit of 0.5 M. The SPCE/PB/copolymer sensor maintained for a long period its response for H2O2 (94% response was retained after 60 days).
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