Electrochemical Characterization of Molecular Conductors Containing Redox Switching Element
Nováková Lachmanová, Štěpánka; Vavrek, František; Sebechlebská, Táňa; Šebera, Jakub; Kolivoška, Viliam; Lukášek, J.; Balzer, N.; Valášek, M.; Mayor, M.; Hromadová, Magdaléna
2021 - English
Electrochemical properties of new molecules containing tripodal anchor and redox switching\nelement have been studied by cyclic voltammetry and DFT quantum mechanical calculations.\nComparison of their redox properties with individual organometallic [Ru(terpy)2]2+t3+ and\n[Os(terpy)2]2+t3+ redox centers shows that covalently bonded tripodal anchor does not\ncompromise the reversibility of a redox process and has no effect on the stability of new\nmolecules. New molecular conductors have smaller HOMO-LUMO gap and both are oxidized\nat only slightly more positive potentials after tripodal substitution making them suitable for the\ndevelopment of molecular conductors with switching abilities.
Keywords:
Tripodal anchor; Cyclic voltammetry; DFT calculations
Available on request at various institutes of the ASCR
Electrochemical Characterization of Molecular Conductors Containing Redox Switching Element
Electrochemical properties of new molecules containing tripodal anchor and redox switching\nelement have been studied by cyclic voltammetry and DFT quantum mechanical calculations.\nComparison of ...
Electroplating of 3D Printed Electrodes for Selective Electrochemical Reduction of C02
Vaněčková, Eva; Bouša, Milan; Shestivska, Violetta; Kubišta, Jiří; Rathouský, Jiří; Sebechlebská, Táňa; Kolivoška, Viliam
2021 - English
In this work, computer assisted design and fused deposition modelling 3D printing are\nemployed to devise and manufacture electrodes from polylactic acid-carbon nanotube\nconductive composite. Electrodes are further modified by copper electroplating to prepare\ncatalysts for the electrochemical reduction of carbon dioxide. Scanning electron microscopy\nand energy dispersive X-ray analysis are used to inspect the surface morphology and chemical\ncomposition of obtained catalysts. Cyclovoltammetric investigations reveal that the copper\nelectroplating leads to the increase of electrode activity by three orders of magnitude.
Keywords:
3D printing; electrochemical reduction of carbon dioxide; electroplating
Available on request at various institutes of the ASCR
Electroplating of 3D Printed Electrodes for Selective Electrochemical Reduction of C02
In this work, computer assisted design and fused deposition modelling 3D printing are\nemployed to devise and manufacture electrodes from polylactic acid-carbon nanotube\nconductive composite. ...
Comparison of the Covalent Laccase Immobilization at Amino- and Carboxylfunctionalized Mesoporous Silica, Glassy Carbon, and Graphite Powders using Different Coupling Agents for Optimal Biosensor Preparation
Tvorynska, Sofiia; Barek, J.; Josypčuk, Bohdan
2021 - English
In order to find the most suitable immobilization protocol, a comparison of three strategies\nbased on the application of –NH2 and –COOH functionalized supports with the different\nactivation agents (glutaraldehyde and carbodiimide) have been conducted for the covalent\nenzyme (laccase) attachment. Two kinds of the supports, namely mesoporous silica (SBA−15,\nMCM−41) and carbonaceous (glassy carbon, graphite) powders, have been used. It was found\nthat a biosensor consisted of tubular detector of silver solid amalgam as a working electrode\nand the enzymatic mini-reactor with laccase covalently attached to glutaraldehyde activated\n–NH2 functionalized MCM−41 shows the best results regarding sensitivity and stability for\ndopamine detection.
Keywords:
Covalent enzyme immobilization; Support surface functionalization; Laccase
Available on request at various institutes of the ASCR
Comparison of the Covalent Laccase Immobilization at Amino- and Carboxylfunctionalized Mesoporous Silica, Glassy Carbon, and Graphite Powders using Different Coupling Agents for Optimal Biosensor Preparation
In order to find the most suitable immobilization protocol, a comparison of three strategies\nbased on the application of –NH2 and –COOH functionalized supports with the different\nactivation agents ...
EPR/UV-VIS-NIR Spectroelectrochemical Examination of the Association Properties of Thienoacene-Bridged Tetrathiafulvalenes Supported by DFT Calculations
Lušpai, Karol; Rapta, P.; Zalibera, M.; Darvasiová, D.; Lukeš, V.
2021 - English
This work was focused on the EPR/UV-VIS-NIR spectroelectrochemical examination of\nassociation properties of radical cations electrochemically produced from tetrathiafulvalene\n(TTF) derivatives, in relation to the molecular structure, mainly the number and orientation of\nthiophene rings in the spacer between fulvalene redox centers. Results from EPR/UV-VIS-NIR\nspectroelectrochemistry were supported by DFT calculations.
Keywords:
Tetrathiafulvalene; EPR/UV-VIS-NIR spectroelectrochemistry; Cyclic voltammetry
Available on request at various institutes of the ASCR
EPR/UV-VIS-NIR Spectroelectrochemical Examination of the Association Properties of Thienoacene-Bridged Tetrathiafulvalenes Supported by DFT Calculations
This work was focused on the EPR/UV-VIS-NIR spectroelectrochemical examination of\nassociation properties of radical cations electrochemically produced from tetrathiafulvalene\n(TTF) derivatives, in ...
UV-Vis and IR Spectroelectrocbemistry of Copper Complexes and Bioactive Compounds
Sokolová, Romana; Obluková, Michaela; Sýs, M.; Mikysek, T.; Wantulok, J.; Nycz, J. E.; Degano, I.
2021 - English
The interpretation of the change of absorption spectrum of an oxidized and reduced molecule\nrecorded during the electron transfer is an efficient tool for the determination of oxidation or\nreduction mechanism. This technique provides the information about the electroactive\nchromophore and is performed in two regimes of electrochemical measurement, cyclic\nvoltammetry and chronoamperometry, respectively. This approach was successfully applied to\nstudy the fundamental electrochemical behavior of recently synthesized copper complexes\nproviding biomimetic activity, ofpolyphenolic bioactive compounds, and also for the reduction\nof halogenated phenanthrolines. The identification of redox products was done by\nchromatographic techniques as HPLC-DAD and HPLC-ESI-MS/MS.
Keywords:
Copper complexes; Catechol; spectroelectrochemistry
Available on request at various institutes of the ASCR
UV-Vis and IR Spectroelectrocbemistry of Copper Complexes and Bioactive Compounds
The interpretation of the change of absorption spectrum of an oxidized and reduced molecule\nrecorded during the electron transfer is an efficient tool for the determination of oxidation or\nreduction ...
Ion Transfer Voltammetry across the Polarized Ionic Liquid/Water Interface: Base for Electrochemical Sensors
Langmaier, Jan; Samec, Zdeněk
2021 - English
Some electrochemical techniques such as voltammetry at the polarized interfaces between two\nimmiscible electrolyte solutions (ITIES) represent interesting alternatives to classical\nelectrochemistry. The benefit of the ion transfer voltammetry lies in the possibility of detection\nof ionic species which are not otherwise redox active. The methodology enables apart of direct\ndetermination of ionic samples (including pharmaceutical and clinical ones) also to monitor\nreaction processes (acido-basic, enzymatic, etc.), determination of reaction substrates and\nproducts in one experimental step, evaluation of reaction and transport kinetics, and estimation\nof lipophilicity of involved species.
Keywords:
ion transfer voltammetry; electrochemical detection; ionic liquid
Available on request at various institutes of the ASCR
Ion Transfer Voltammetry across the Polarized Ionic Liquid/Water Interface: Base for Electrochemical Sensors
Some electrochemical techniques such as voltammetry at the polarized interfaces between two\nimmiscible electrolyte solutions (ITIES) represent interesting alternatives to classical\nelectrochemistry. ...
The use of Boron Doped Diamond Electrode for Determination of 5-hydroxyindoleacetic Acid
Hrdlička, Vojtěch; Navrátil, Tomáš
2021 - English
A new method for voltammetric determination of clinical biomarker 5-hydroxyindoleacetic\nacid (HIAA) at the boron-doped diamond electrode (BDDE) was developed. Anodically and\ncathodically pretreated BDDEs were tested in the pH ranges from 1 to 12, pre-treatment at\n+2.0V/60 s, and pH 3 was found to be the optimum.\nThe optimum square wave voltammetry (SWV) parameters were: f = 12 Hz, amplitude 60\nmV, and potential step 4 mV. SWV concentration dependency was constructed in the range\nfrom 0.1 to 100 μmol L−1, limits of determination and detection were 0.3 and 0.1 μmol L−1,\nrespectively. HIAA oxidation electrode process at BDDE was diffusion-controlled, as\nuncovered by cyclic voltammetry. Interestingly, HIAA peak potential was constant in various\nranges of pH, indicating a non-Nernstian behavior at the BDDE, in contrast to a previously\npublished electrooxidation mechanism consisting of a coupled H+/e− transfer.
Keywords:
boron-doped diamond electrode; 5-hydroxyindoleacetic acid; square wave voltammetry
Available on request at various institutes of the ASCR
The use of Boron Doped Diamond Electrode for Determination of 5-hydroxyindoleacetic Acid
A new method for voltammetric determination of clinical biomarker 5-hydroxyindoleacetic\nacid (HIAA) at the boron-doped diamond electrode (BDDE) was developed. Anodically and\ncathodically pretreated ...
Determination of Selected Drugs using 3D Printed Electrodes
Choińska-Mlynarczyk, Marta; Hrdlička, Vojtěch; Navrátil, Tomáš
2021 - English
The main aim of this research was to develop a new method for voltammetric determination of\npopular antidepressants, analgesics, and illicit drugs using a laboratory-made 3D printed\nelectrode and to compare the achieved results with those registered using a commercially\navailable glassy carbon electrode. These experiments represent the first step in the development\nof a method applicable in clinical and forensic praxis for the rapid and inexpensive\ndetermination of commonly misused groups of biologically active compounds.
Keywords:
analgesics; antidepressants; biologically active compounds
Available on request at various institutes of the ASCR
Determination of Selected Drugs using 3D Printed Electrodes
The main aim of this research was to develop a new method for voltammetric determination of\npopular antidepressants, analgesics, and illicit drugs using a laboratory-made 3D printed\nelectrode and to ...
Determination of heavy metal poisoning antidote 2,3-dimercapto-1-propanesulfonic acid using silver solid amalgam electrode
Choińska-Mlynarczyk, Marta; Hrdlička, Vojtěch; Redondo, B. R.; Barek, J.; Navrátil, Tomáš
2020 - English
2,3-Dimercapto-1-propane-sulfonic acid (DMPS) was investigated using direct current voltammetry (DCV), differential pulse cathodic stripping voltammetry (DPCSV), differential pulse anodic stripping voltammetry (DPASV), and elimination voltammetry with linear scan (EVLS) at a polished (p-AgSAE)and at a meniscus modified silver solid amalgam electrode (m-AgSAE). EVLS confirmed two consecutive reductions with coupled proton/electron transfer. Voltammetric titrations of DMPS with Pb2+ proved complex formation, with limits of quantification (LOQs) and detection (LODs) 0.3 and 0.1 mu mol L-1 at m-AgSAE and 0.8 and 0.3 mu mol L-1 at p-AgSAE, respectively. Determination of DMPS in commercial drug Dimaval and human urine samples confirmed practical applicability of the developed method.
Keywords:
cathodic stripping voltammetry; 2,3-dimercapto-1-pro-panesulfonic acid; elimination voltammetry with linear scan
Available on request at various institutes of the ASCR
Determination of heavy metal poisoning antidote 2,3-dimercapto-1-propanesulfonic acid using silver solid amalgam electrode
2,3-Dimercapto-1-propane-sulfonic acid (DMPS) was investigated using direct current voltammetry (DCV), differential pulse cathodic stripping voltammetry (DPCSV), differential pulse anodic stripping ...
Charge Transport in Single Oligophenylene Molecular Wires with Different Anchoring Groups
Hromadová, Magdaléna; Kolivoška, Viliam; Šebera, Jakub; Sebechlebská, Táňa; Gasior, Jindřich; Nováková Lachmanová, Štěpánka; Mészáros, G.; Lindner, M.; Mayor, M.; Valášek, M.
2019 - English
This work compares single molecule conductance measurements of selected organic systems containing identical oligophenylene molecular wires and different tripodal anchoring groups. Single molecule conductance G was obtained by a scanning tunneling microscopy break junction technique complemented by theoretical calculations based on the density functional theory and non-equilibrium Green’s function formalism. Two molecules were compared where the same oligophenylene wire is connected to one of the electrodes via a tripod substituted on each leg by a thiol group either in the meta or para position. By combined experimental and theoretical analysis it was possible to confirm that single molecule conductance in the metal-molecule-metal junction of both molecules corresponds to a fully extended molecular wire, which is attached to one of the electrodes by all three thiolate bonds of the tripod. Experimental results confirmed that G value of meta-connected molecules is lower than that of para, whereas junction formation probability was higher for meta functionalization.
Keywords:
STM break junction; Tetraphenylmethane Tripodal anchor; Single molecule conductance
Available at various institutes of the ASCR
Charge Transport in Single Oligophenylene Molecular Wires with Different Anchoring Groups
This work compares single molecule conductance measurements of selected organic systems containing identical oligophenylene molecular wires and different tripodal anchoring groups. Single molecule ...
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