TY - JOUR AU - Kiss, László AU - Szabó, Péter AU - Kunsági-Máté, Sándor TI - Comparison between Electrooxidation of 1-Naphthol and 2-Naphthol in Different Non-Aqueous Solvents and Suppression of Layer Growth of Polymers JF - SURFACES J2 - SURFACES-BASEL VL - 7 PY - 2024 IS - 1 SP - 164 EP - 180 PG - 17 SN - 2571-9637 DO - 10.3390/surfaces7010011 UR - https://m2.mtmt.hu/api/publication/34777126 ID - 34777126 N1 - Funding Agency and Grant Number: Hungarian National Research Development and Innovation Office (NKFI) Funding text: No Statement Available AB - The two naphthol isomers were investigated in different organic solvents by taking cyclic voltammograms, and fouling took place on a platinum electrode surface, except for dimethyl sulfoxide and dimethyl formamide. Studies in allyl alcohol rarely used in electrochemical investigations pointed to the importance of the carbon-carbon double bond as electrode deactivation was remarkably faster compared with its saturated analog solvent. Similarly, the use of the other unsaturated solvent mesityl oxide in the electropolymerization of naphthols resulted in different findings compared with methyl isobutyl ketone. As dimethyl formamide was the best choice concerning the solubility of products, it was successfully tested in electrode renewal after deactivation in an aqueous solution. The increase in dimethyl formamide content led to more and more improved reproducibility of the currents of the outlined aromatic compounds. Naphthol isomers were assessed in the suppression of layer growth originating from the electrooxidation of another monomer phloroglucinol. Its simultaneous electrooxidation with naphthol monomers had a dramatic effect on layer morphology and it was found that instead of a coherent organic layer originating from the homopolymerization of phloroglucinol, the copolymerization with naphthols led to the development of more porous and rougher deposits. The suppressed electropolymerization thus increased sensitivity towards a chosen redox active compound, 4-methoxyphenol. LA - English DB - MTMT ER - TY - JOUR AU - Kiss, László AU - Kunsági-Máté, Sándor AU - Szabó, Péter TI - Studies of Phenol Electrooxidation Performed on Platinum Electrode in Dimethyl Sulphoxide Medium. Determination of Unreacted Phenol by the Effect of 4-vinylbenzenesulphonate on the Electrooxidation Process JF - ELECTROANALYSIS J2 - ELECTROANAL VL - 35 PY - 2023 IS - 4 PG - 9 SN - 1040-0397 DO - 10.1002/elan.202200268 UR - https://m2.mtmt.hu/api/publication/33204828 ID - 33204828 LA - English DB - MTMT ER - TY - JOUR AU - Kiss, László AU - Kunsági-Máté, Sándor TI - Scan rate and concentration dependence of the voltammograms of substituted phenols on electrodes with different size, diffusion coefficients of phenols in different solvents JF - CANADIAN JOURNAL OF CHEMISTRY J2 - CAN J CHEM VL - 101 PY - 2023 IS - 5 SP - 297 EP - 305 PG - 9 SN - 0008-4042 DO - 10.1139/cjc-2022-0096 UR - https://m2.mtmt.hu/api/publication/33688939 ID - 33688939 AB - In this work, the effects of the scan rate and the concentration of the substituted phenols on the peak currents or current plateaus have been investigated. Voltammetric curves recorded by a platinum microelectrode varied significantly under different experimental conditions in cases of 4-chlorophenol, 4- tert-butylphenol, and 4-nitrophenol. In the case of 4-methoxyphenol and 4- tert-butylphenol, when the experiments were performed in the lower concentration range in acetonitrile, the plateau current and peak current showed linear dependence on phenol concentration. Therefore, these ranges offer opportunity for further characterization. The electrode reaction of 4-methoxyphenol was found to be a diffusion-controlled process in the solvents applied (water, acetonitrile, dimethyl sulfoxide, dimethyl formamide, nitrobenzene, acetone, dichloromethane, methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol). Diffusion coefficients of 4-methoxyphenol were determined with a microelectrode using the steady-state voltammograms. Diffusion coefficients of other phenols were measured only in acetonitrile with a macroelectrode. In agreement with known theories, the diffusion coefficients showed inversely proportional relationships with the solvent viscosities. Special care was needed in 1-pentanol solvent since the increasing anodic peaks appeared after the first scan and overlaid with the sigmoidal-shaped regular microelectrode voltammograms. This observation is probably due to formation of adhering residual electroactive products. LA - English DB - MTMT ER - TY - JOUR AU - Kiss, László AU - Nagymihaly, Zoltan AU - Szabó, Péter AU - Kollár, László AU - Kunsági-Máté, Sándor TI - Detection of Residual 2-Phenylphenol on Lemon Rind by Electrochemically Deposited Poly(hydroxybenzaldehyde) and Poly(hydroxybenzoic acid) Polymeric Stackings as Electrode Modifiers JF - MATERIALS J2 - MATERIALS VL - 16 PY - 2023 IS - 1 PG - 12 SN - 1996-1944 DO - 10.3390/ma16010357 UR - https://m2.mtmt.hu/api/publication/33550179 ID - 33550179 AB - This study explores the characteristics of electrodeposition of the three hydroxybenzaldehyde isomers and selected hydroxybenzoic acids (4-hydroxybenzoic acid, salicylic acid, 3,5-dihydroxybenzoic acid) from mesityl oxide solvent. Similar to recent advances of this solvent, used by electrochemical studies, the carbon–carbon double bond had significant influence on the formation of polymers from the outlined molecules. In case of most substrates the peak currents increased to a steady-state but electropolymerization of some substrates caused significant deactivation. Scanning electron microscopic and complementary voltammetric studies facilitated that the electrochemically formed polymers are present on the electrode surface in stackings. In viewpoint of analysis of 2-phenylphenol, the modifying deposit formed from 4-hydroxybenzaldehyde was the best with 5 µM detection limit obtained with differential pulse voltammetry. Furthermore, a new procedure was chosen for the involvement of a cavitand derivative into the organic layers with the purpose to improve the layer selectivity (subsequent electrochemical polymerization in an other solution). Further studies showed that in this way the sensitivities of as-modified electrodes were a little worse than without this step, thus indicating that application of this step is disadvantageous. Recovery studies of 2-phenylphenol were carried out on lemon rind without any treatment, and it was compared with the case when the outer yellow layer was removed by rasping. The inner tissues showed very high adsorption affinity towards 2-phenylphenol. LA - English DB - MTMT ER - TY - JOUR AU - Kiss, László AU - Nagymihaly, Zoltan AU - Kollár, László AU - Kunsági-Máté, Sándor TI - Voltammetric and Fluorimetric Studies of Dibenzoylmethane on Glassy Carbon Electrodes and Its Interaction with Tetrakis (3,5-Dicarboxyphenoxy) Cavitand Derivative JF - MOLECULES J2 - MOLECULES VL - 28 PY - 2023 IS - 1 PG - 9 SN - 1420-3049 DO - 10.3390/molecules28010185 UR - https://m2.mtmt.hu/api/publication/33550159 ID - 33550159 AB - Due to the medical importance of dibenzoylmethane, one of the aims of the study was to find an appropriate packing material and a biologically friendly co-solvent to help its introduction into living systems. Accordingly, redox properties of dibenzoylmethane were investigated on glassy carbon electrodes in acetonitrile and in 1-propanol with cyclic voltammetry, and showed a diffusion-controlled process. In the anodic window, an oxidation peak appeared at around 1.9 V in both solvents. Cycling repeatedly between 0 and 2 V, the reproducibility of this peak was acceptable, but when extending the window to higher potentials, the electrode deactivated, obviously due to electrode material. The addition of the investigated tetrakis(3,5-dicarboxyphenoxy) cavitand did not significantly change the voltammograms. Further electrochemical experiments showed that the coexistence of water in acetonitrile and 1-propanol drastically reduces the solubility of dibenzoylmethane. Moreover, very rapid electrode deactivation occurred and this fact made the use of electrochemical methods complicated. Considering that both the cavitand and dibenzoylmethane are soluble in dimethyl sulfoxide, the interaction of these species was investigated and formation of stable complexes was detected. This observation was verified with fluorescence quenching studies. The mixture of water and dimethyl sulphoxide also dramatically improved the solubility of the cavitand–dibenzoylmethane complex at high excess of water. The addition of cavitand improved the solubility of dibenzoylmethane, a property which supports the application of dibenzoylmethane in therapy. LA - English DB - MTMT ER - TY - JOUR AU - Sowad, R.S.R.B. AU - Kiss, László AU - Kiss, András TI - Conductivity mapping of topographically complex surfaces using contact-mode carbon fibre in potentiometric SECM JF - ELECTROCHEMISTRY COMMUNICATIONS J2 - ELECTROCHEM COMMUN VL - 152 PY - 2023 PG - 6 SN - 1388-2481 DO - 10.1016/j.elecom.2023.107515 UR - https://m2.mtmt.hu/api/publication/34050086 ID - 34050086 LA - English DB - MTMT ER - TY - JOUR AU - Budetić, Mateja AU - Samardžić, Mirela AU - Bubnjar, Karlo AU - Dandić, Andrea AU - Živković, Pavo AU - Széchenyi, Aleksandar AU - Kiss, László TI - A new sensor for direct potentiometric determination of thiabendazole in fruit peels using the Gran method JF - FOOD CHEMISTRY J2 - FOOD CHEM VL - 392 PY - 2022 PG - 26 SN - 0308-8146 DO - 10.1016/j.foodchem.2022.133290 UR - https://m2.mtmt.hu/api/publication/32843480 ID - 32843480 LA - English DB - MTMT ER - TY - JOUR AU - Kiss, László AU - Nagymihaly, Zoltan AU - Szabó, Péter AU - Kollár, László AU - Kunsági-Máté, Sándor TI - Anodic Polymerization of Phenylphenols in Methyl Isobutyl Ketone and Mesityl Oxide: Incorporation of a Cavitand into the Layers Formed for Sensing Phenols in Organic Media JF - MOLECULES J2 - MOLECULES VL - 27 PY - 2022 IS - 17 PG - 16 SN - 1420-3049 DO - 10.3390/molecules27175366 UR - https://m2.mtmt.hu/api/publication/33080537 ID - 33080537 AB - The electropolymerization of three phenylphenol isomers was studied in methyl isobutyl ketone and mesityl oxide, and the remarkable differences highlighted the importance of the carbon–carbon double bond in mesityl oxide. In the case of each substrate, a brownish deposit formed during the electrooxidation. The obvious difference between the polymers formed from the two solvents was recognized via voltammetric signal enhancement of 4-methoxyphenol and 4-chlorophenol, and it was only observed in the case of mesityl oxide. The experiments highlighted that incorporation of a cavitand with biphenyl groups on the upper rim of the polymers of phenylphenols improved the results to a small extent. The cavitand was, itself, electroactive without any fouling effect. As 2-phenylphenol is by far the cheapest of the three isomers, a cavitand was incorporated into its polymer, which was exploited to solve analytical problems while mesityl oxide was used as solvent. Useful quantifications were achieved in organic solvents; however, it failed under aqueous conditions due to the high hydrophobicity of the deposit. Application of differential pulse voltammetry for 4-methoxyphenol and 4-chlorophenol gave detection limits of 9.28 and 50.8 μM in acetonitrile, respectively. This procedure resulted in the immobilization of cavitand derivatives onto the electrode’s surface, and the layer formed offered selective sensing of phenols by electrochemical methods. LA - English DB - MTMT ER - TY - JOUR AU - Kiss, László TI - Coexistence of Substituted Phenols Reduces the Fouling Ability of Phenol in Non-aqueous Solvents JF - PERIODICA POLYTECHNICA-CHEMICAL ENGINEERING J2 - PERIOD POLYTECH CHEM ENG VL - 66 PY - 2022 IS - 3 SP - 409 EP - 413 PG - 5 SN - 0324-5853 DO - 10.3311/PPch.18008 UR - https://m2.mtmt.hu/api/publication/33063813 ID - 33063813 AB - The electrooxidation of phenol showed different rate of deactivation by varying the concentration of substituted phenols (4-chlorophenol, 4-methoxyphenol, 4-tert-butylphenol). This was due to the more favourable solubility properties of the product copolymers compared with poly(phenyleneoxide) the product which forms when only unsubstituted phenol is present. The nature of substituent, switching potential and oxidation potentials of the studied phenols were significant in prevention of electrode fouling. The best reproducibility could be achived upon addition of 4-chlorophenol. This offered a possibility for estimation of phenol concentration in non-aqueous systems. LA - English DB - MTMT ER - TY - JOUR AU - Kiss, László TI - Electrode Processes of 1,2,4-benzenetriol in Different non-aqueous Solvents JF - REVISTA DE CHIMIE J2 - REV CHIM-BUCHAREST VL - 73 PY - 2022 IS - 4 SP - 1 EP - 8 PG - 8 SN - 0034-7752 DO - 10.37358/RC.22.4.8541 UR - https://m2.mtmt.hu/api/publication/33210389 ID - 33210389 AB - The electrooxidation of 1,2,4-benzenetriol was studied in different non-aqueous solvents. The results showed that the studied substance can be oxidized in several ways on the electrode surface due to the favourable positions of hydroxyl groups (similarly to hydroquinone, resorcinol and catechol). In most cases one anodic peak appeared involving all possible electrode processes. The concentration dependence of voltammetric peak currents using platinum macroelectrode showed nonlinearity attributable to the 1,3-oxidation similarly to resorcinol leading to partial deactivation. Appearance of more peaks indicated the weak deactivation at higher concentrations in acetonitrile and nitrobenzene. At higher concentration the microelectrode became deactivated as in the successive scans the currents declined continuously reinforcing the existence of resorcinol pathway. LA - English DB - MTMT ER -