NAFION-CROWN ETHER MODIFIED CARBON-FIBER ELECTRODES - NEW MICROBIOSENSORS FOR DETECTION OF NEUROTRANSMITTERS IN-VITRO AND IN-VIVO

Based on experience in in vivo voltammetry with Nafion carbon fiber electrode coated (CFE), a new kind of modification, was developed based on mixing Nafion and crown ether (dibenzo-18-crown-6) solutions. Nafion-crown ether electrodes (NA-CRO-CFEs) offer higher sensitivity to dopamine than Nafion-CFEs. The improvement of detection limit is caused by enrichment of the neurotransmitter in polymermembrane by interaction of oxygen atoms of the crown ether and the positively charged amino group of catecholamine. With NA-CRO-CFEs one is able to detect dopamine and serotonin in physiological basal concentrations in vitro and in vivo without overlapping of oxidation peaks of ascorbic acid or metabolites. Identification of in vivo peaks is discussed with in vitro and in vivo experiments.