8/2013-14 Sensing in Electroanalysis
Permanentní URI k tomuto záznamuhttps://hdl.handle.net/10195/56677
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Článekpeer-reviewedpublished Otevřený přístup Electrochemical sensor for histamine determination based on zinc oxide thin films electrodeposited on carbon paste electrodes(Univerzita Pardubice, 2014) Pekec, Bruna; Hauser, Susanne; Kalcher, Kurt; Ortner, AstridHistamine, a biogenic amine and important mediator of inflammation was quantitatively analysed using electrochemical techniques. The sensor designed in this context based on carbon paste (CP) as electrode material and zinc oxide (ZnO) as modifier to increase the selectivity, due to the strong complex building tendency of the imidazole ring to metals. Using an alkaline electrolyte medium the oxidation potential was shifted from + 1.20 V in neutral medium to a less positive value of + 0.750 V vs. Ag/AgCl. A logarithmic correlation for a concentration range from 5 to 500 μg/mL could be found. The developed ZnO-CP based sensor, characterized by a precision (R.S.D.) of 5.8 % and an accuracy of 5.2 % was successfully tested in complex food matrix.Článekpeer-reviewedpublished Otevřený přístup On the performance of amperometric tyrosinase carbon paste biosensor in the presence of catechol, resorcinol, or hydroquinone(Univerzita Pardubice, 2014) Sýs, Milan; Metelka, Radovan; Vytřas, KarelThis study was aimed to understand which substitution position of hydroxy groups on benzene ring is the most suitable for active site of enzyme tyrosinase, and also to determine if tyrosinase is a useful biological component for the development a biosensor based on carbon material for the determination of polyphenolic compounds in food samples. Electrochemical properties of diphenols (catechol, resorcinol, and hydroquinone) at bare carbon paste electrode (CPE) and CPE surface-modified with conductive copolymer Nafion and enzyme mushroom tyrosinase (CPE/Tyr/Nafion) were investigated using cyclic voltammetry and hydrodynamic amperometry.Článekpeer-reviewedpublished Otevřený přístup Electrochemical behavior of triethanolamine at a carbon paste electrode(Univerzita Pardubice, 2014) Karastogianni, Sophia; Girousi, StellaIn this article, the electrochemical behavior of triethanolimine is described with a carbon paste electrode. A differential pulse voltammetric method was also developed for the determination of triethanolamine as an application to electroanalysis at a carbon paste electrode. The resultant voltammograms have revealed the irreversible electrochemical process that can be utilized to quantify the substances of interest, for triethanolamine, for which the detection limit (3σ) was estimated to be 2.8 × 10−5 mol L−1.Článekpeer-reviewedpublished Otevřený přístup New applications of carbon paste electrodes for determination of biologically active organic compoun(Univerzita Pardubice, 2014) Zima, Jiří; Barek, Jiří; Dejmková, Hana; Wang, JosephIn this paper, new electrochemical determinations of selected biologically active compounds are described employing various types of carbon paste electrodes (CPE) in batch voltammetric methods (differential pulse voltammetry (DPV), direct current voltammetry (DCV), and cyclic voltammetry (CV)) and in HPLC with electrochemical detection (HPLC-ED) utilizing amperometric CPE sensors. The results for determination of cymoxanil, famoxadone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, chlortoluron, carboxin, triclosan, diafenthiuron, and propyl gallate are compared and discussed. Glassy carbon spherical microparticles were used as carbonaceous component of the paste. The limits of detection of some analytes were below 1·10-7 mol l-1 in both batch and flow methods. The newly developed methods of determination were applied to model samples of drinking and river water, soils, and practical samples of edible oil, toothpaste, soap, and toilet water.Článekpeer-reviewedpublished Otevřený přístup Carbon paste electrodes bulk-modified with carbon nanotubes and chemically oxidized carbon nanotubes for the determination of hydrogen peroxide(Univerzita Pardubice, 2014) Zbiljić, Jasmina; Vajdle, Olga; Guzsvány, Valéria; Kónya, Zoltán; Kukovecz, Ákos; Dalmacija, Božo; Kalcher, KurtCarbon paste electrodes (graphite/paraffin oil) bulk-modified with multiwalled carbon nanotubes (MWCNT) and chemically oxidized MWCNT (O-MWCNT) were used as sensors for the hydrodynamic chronoamperometric determination of hydrogen peroxide (H2O2). Experimental parameters, such as the type and pH of the supporting electrolyte or the working potential(s) applied were investigated in the batch arrangement.Článekpeer-reviewedpublished Otevřený přístup Construction and evaluation of a carbon paste electrode modified with polyaniline-co-poly(dithiodianiline) for enhanced stripping voltammetric determination of metal ions(Univerzita Pardubice, 2014) Somerset, Vernon; Silwana, Bongiwe; Horst, Charlton van der; Iwuoha, EmmanuelA modified carbon paste electrodes (MCPE) have been prepared in this study as an alternative “mercury-free” electrochemical sensor for the determination of Pb2+ and Cd2+ metal ions in aqueous solutions. CPE containing a conducting copolymer of polyaniline-co-poly(2,2'- dithiodianiline) (PANI-co-PDTDA) was used as a modified substrate transducer to achieve enhanced selectivity in stripping voltammetric analysis. The experimental conditions optimised included the supporting electrolyte pH, deposition potential (Ed) and time (td), set at −0.6 V vs. ref. for Pb2+ and −0.8 V for Cd2+; both kept for td = 120 s. The results with the CPE/PANI-co- PDTDA sensor have revealed the linear range within the range of 0.15 – 0.5 μg/L for Pb2+ and the same interval for Cd2+. Finally, the electrode of interest, CPE/PANI-co-PDTDA, can be characterised by the LODs of 0.03 and 0.09 μg/L for Pb2+ and Cd2+ respectively.Článekpeer-reviewedpublished Otevřený přístup Traditional vs. non-traditional materials for carbon paste electrode preparation: on relation between the composition and properties(Univerzita Pardubice, 2014) Mikysek, Tomáš; Rosecká, Kamila; Stočes, Matěj; Kalcher, Kurt; Švancara, IvanSeveral new types of carbon pastes were prepared as well as pastes made from various abrasive materials, examined and characterized. The main attention has been paid to the changes in their ohmic resistance, relative to the dependence on the composition of powder material to paraffin oil as pasting liquid. The results were compared with those of “traditional” carbon paste electrodes based on graphite powder and the differences in physical as well as electrochemical properties were discussed and explained. As found, the most evident difference was in the optimal carbon-to-binder ratio of the paste.