TY - GEN A1 - Roznyatovskaya, Nataliya V. A1 - Laurinavichyute, Veronika K. A1 - Tsirlina, Galina A. A1 - Mirsky, Vladimir M. T1 - Electrochemistry and catalytic behavior of immobilized binuclear complexes of copper(II) and nickel(II) with Robson type ligand T2 - Journal of Solid State Electrochemistry N2 - Various systems containing immobilized binuclear copper(II) and nickel(II) complexes with Robson type ligand ([M2L]Cl2) are studied and compared in relation to catalysis of hydrogen peroxide reduction. Molecular complexes adsorbed on mercury and gold, crystalline complexes immobilized in the carbon paste electrode, and complex species entrapped into polyphenol-modified gold electrodes are considered. Electrocatalysis is assumed to result from the formation of H2O2–[M2L]Cl2 adduct, not from mediating redox transformations. Possible geometry of the formed reaction layers supporting adduct formation is discussed. KW - Binuclear copper macrocyclic complex KW - Cyclic voltammetry KW - Adsorption KW - Carbon paste electrodes KW - Electroreduction Y1 - 2007 U6 - https://doi.org/10.1007/s10008-006-0235-7 SN - 1432-8488 SN - 1433-0768 VL - 11 IS - 7 SP - 981 EP - 992 ER - TY - GEN A1 - Laurinavichyute, Veronika K. A1 - Nizamov, Shavkat A1 - Mirsky, Vladimir M. T1 - The Role of Anion Adsorption in the Effect of Electrode Potential on Surface Plasmon Resonance Response T2 - ChemPhysChem : a European journal of physical chemistry and chemical physics N2 - Surface plasmon resonance, being widely used in bioanalytics and biotechnology, is influenced by the electrical potential of the resonant gold layer. To evaluate the mechanism of this effect, we have studied it in solutions of various inorganic electrolytes. The magnitude of the effect decreases according to the series: KBr>KCl>KF>NaClO4. The data were treated by using different models of the interface. A quantitative description was obtained for the model, which takes into account the local dielectric function of gold being affected by the free electron charge, diffuse ionic layer near the gold/water interface, and specific adsorption of halides to the gold surface with partial charge transfer. Taking into account that most biological experiments are performed in chloride-containing solutions, detailed analysis of the model at these conditions was performed. The results indicate that the chloride adsorption is the main mechanism for the influence of potential on the surface plasmon resonance. The dependencies of surface concentration and residual charge of chloride on the applied potential were determined. Y1 - 2017 U6 - https://doi.org/10.1002/cphc.201601288 SN - 1439-7641 SN - 1439-4235 VL - 18 IS - 12 SP - 1552 EP - 1560 ER - TY - GEN A1 - Laurinavichyute, Veronika K. A1 - Nizamov, Shavkat A1 - Mirsky, Vladimir M. T1 - Real time tracking of the early stage of electrochemical nucleation T2 - Electrochimica Acta N2 - An analysis of early stage of electrochemical nucleation is crucial in order to understand the mechanism of this process and for electrochemical synthesis of new materials. We show here an application of the wide field surface plasmon microscopy (WF-SPRM) for this purpose. It allows us in-situ monitoring of the growth of nuclei in the range from ~20 till over 1000 nm. The system registers the moment and the place of the formation of each individual nucleus for the total number of the tracked nuclei up to ~10,000 per 1 mm2. The results demonstrate that the integral information obtained from electrochemical measurements can be extracted quantitatively from optical measurements while optical data provide also information on the size of each individual nucleus, individual nucleation time, localization and growth kinetics, and allows one to distinguish the rate limiting stage for each individual nucleus. In this work WF-SPRM was applied for investigation of electrochemical deposition of copper on gold, but this technique can be extended easily to other materials or other nucleation types. KW - Surface plasmon resonance microscopy KW - Nucleation and growth KW - Copper deposition KW - Growth kinetics KW - Diffusion zones Y1 - 2021 U6 - https://doi.org/10.1016/j.electacta.2021.138278 SN - 0013-4686 VL - 382 ER - TY - GEN A1 - Kolosova, Olga S. A1 - Efremenko, Yulia A1 - Laurinavichyute, Veronika K. A1 - Nizamov, Shavkat A1 - Petrushenko, Serhii I. A1 - Mirsky, Vladimir M. T1 - Poly-3-thienylboronic Acid Nanoparticles: Synthesis, Characterization, and Interaction with Saccharides Studied at the Level of Individual Nanoparticles T2 - ACS Applied Nano Materials N2 - Polythiophenboronic acid (PThBA) combines an affinity for saccharides with the unique properties of conducting polymers. This polymer was synthesized by enzymatic catalyzed oxidative polymerization, characterized by UV–vis spectroscopy in solvents of different polarity and by 1H NMR. A suspension of PThBA nanoparticles (PThBA NPs) was prepared by injecting a methanol solution of PThBA into an aqueous electrolyte. PThBA NPs were characterized by scanning electron microscopy. Nanoparticle tracking analysis and dynamic light scattering were used to study the concentration of the particles and the particle size distribution. The effect of pH on these properties was analyzed and an increase in nanoparticle size was observed at alkaline pH. This effect was explained by electrostatic swelling of the nanoparticles. Measurements of ζ-potentials in the wide pH range showed the presence of acidic groups with a pKa of 8.6; the value of the surface charge at the conditions of maximal deprotonation of these groups was estimated to be ∼70 mC/m2. Changes in the optical spectra of PThBA NPs due to variations in pH and additions of organic solvents indicate transformations between twisted and planar conformations of the polymer backbone. The binding of saccharides by PThBA NPs resulted in a decrease in the size and charge of the nanoparticles. Recently developed wide-field surface plasmon resonance microscopy (WF-SPRM) can simultaneously monitor every single nanoparticle among many thousands adsorbed on a surface. It was used for the first time to study chemosensitive nanoparticles. The described above effects of pH change and saccharide binding described above, monitor were confirmed by using integral techniques in monitoring individual nanoparticles, by WF-SPRM. The pH effects were shown to be reversible. An increase in the affinity of PThBA NPs for saccharides at a more alkaline pH was also observed. A fast recovery of polymer binding sites by a pH decrease was demonstrated. The synthesized and characterized PThBA NPs can be further used for various purposes including analytical assays, chemical sensors, or chemosensitive nanotechnological devices. KW - - KW - conducting polymers KW - chemosensitive nanoparticles KW - saccharides binding KW - affinity control KW - polythienylboronic acid KW - surface plasmon resonance microscopy Y1 - 2024 U6 - https://doi.org/10.1021/acsanm.4c00216 SN - 2574-0970 VL - 7 IS - 10 SP - 11120 EP - 11135 PB - American Chemical Society ER -