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In this work we report the electrochemical, spectroscopical and spectro-electrochemical studies of a model complex [CuΙΙ(Bztpen)]2+, (Bztpen = (N-benzyl-N,N′,N′-tris(pyridin-2-ylmethyl)ethylenediamine) in order to propose a methodology to evaluate the interaction of potential metal based anticancer agents during electron transfer processes, with transport proteins such as Bovine Serum Albumin (BSA). It was possible to establish a reversible electron transfer [CuΙΙ(Bztpen)]2+ +1e → [CuΙ(Bztpen)]+ and a weak interaction energy between BSA and [CuΙΙ(Bztpen)] and [CuΙ(Bztpen)] species, with no adsorption of protein over the electrode surface. Circular Dichroism (CD) Spectroelectrochemistry, not reported before, reveals no significant changes in BSA structure during the electron transfer [CuΙΙ(Bztpen)]2+ + 1e → [CuΙ(Bztpen)]+. CD experiments at variable temperature for BSA denaturalization in the absence and in the presence of [CuΙΙ(Bztpen)]2+, shown no change in thermodynamic parameters due to low interaction between the transport protein and copper complex. In this work we report the interaction of the complex [Cu(Bztpen)]2+ with Bovine Serum Albumin (BSA) using UV-vis spectroscopy, CD experiments at variable temperature, DFT calculations, electrochemical and CD-spectroelectrochemistry. [Display omitted] • A Cu complex with the ligand Bztepen (N-benzyl-N,N'′,N'′-tris(pyridin-2-ylmethyl)ethylenediamine) is prepared. • It was established the redox process [Cu(Bztpen)]2+ +1e → [Cu(Bztpen)]+. • It was found a weak interaction between BSA and [Cu(Bztpen)]2+/ [Cu(Bztpen)]+. • CD-spectroelectrochemistry reveals no changes during the electron transfer processes. [ABSTRACT FROM AUTHOR]

The production of human recombinant proteins to be used for therapeutic or nutritional purposes must focus on obtaining a molecule that is as close as possible to the native human protein. This biotechnological tool has been documented in various studies published in recent decades, with lactoferrin being one of those that has generated the most interest, being a promising option for recombinant technology. However, stability studies including thermodynamic parameters have not been reported for recombinant lactoferrin (Lf). The objective of this work was to obtain the human recombinant protein using the yeast Komagataella phaffii to study structural changes modifying pH and temperature using circular dichroism spectroscopy (CD). Thermodynamic parameters such as ΔH, ΔS and Tm were calculated and compared with commercial human lactoferrin. We propose the potential use of CD and thermodynamic parameters as a criterion in the production of recombinant proteins to be used in the production of specialized recombinant proteins. [ABSTRACT FROM AUTHOR]

[Display omitted] • Relationship between synthesis pH and rugosity of the coatings has been assessed. • The alkaline pH affects the synthesis in situ of the TiO 2 nanoparticles. • The use of HMDS improve the self-cleaning properties of the SiO 2 -TiO 2 coating. • The use of TiO 2 nanoparticles changes from hydrophobic state to a hydrophilic state. The SiO 2 -TiO 2 composite has been studied through several techniques obtaining different morphologies and specific properties of SiO 2 and TiO 2. Nevertheless, the modification of the synthesis pH and the addition of different hydrophobic agents, such as hexamethyldisilazane (HDMS) and polydimethylsiloxane (PDMS), have not been thoroughly studied and reported. This work assessed the presence of two different hydrophobic agents and the pH modification. The SiO 2 -TiO 2 coating was synthesized through two vias, basic and acid environment, employing the sol–gel method coupled to the sonochemistry technique. Moreover, the change of pH and use of P25 TiO 2 nanoparticles and TiO 2 -synthesized nanoparticles allows establishing a relationship with the self-cleaning properties. The samples of SiO 2 -TiO 2 composite were analyzed by AFM, indicating a variation in surface morphology and roughness concerning the PDMS and HMDS hydrophobic agent. ATR-FTIR analysis exhibit changes in intensity in vibrations of the Si-O, PDMS, and HMDS bonds. Raman spectroscopy results show the vibrations of the anatase and rutile phases of the TiO 2 and the corresponding vibrations to the hydrophobic agents. The evaluation of self-cleaning properties demonstrated changes from the hydrophobic state to the hydrophilic state due to the addition of the nanoparticles of TiO 2 to the SiO 2. The photocatalytic activity was modified and improved in the HMDS-1 coating due to the hydrophobic agent and type of nanoparticles. To compare the effect of the pH in the PDMS and HMDS coatings, carried out with cyclic voltammograms and Differential Capacitance spectra. Finally, the storage time of SiO 2 -TiO 2 coating was improved using the HMDS hydrophobic agent. [ABSTRACT FROM AUTHOR]

• Full characterization of NiII( tpa ) complexes gives information about its electronic structure which corelates with electrochemical behavior. • NiII( tpa ) complexes presented tunable redox potential for the NiII/NiI reduction. • NiII complex with more negative redox potential presented the high catalytic activity for CO 2 reduction. • Theoretical approach was useful for the analysis and description of electrochemical mechanisms. In this paper, we report the synthesis, characterization, as well as electrochemical, spectroelectrochemical, and density functional theory (DFT) calculations of a series of novel NiII complexes with a flexible tetradentate ligand, tris(2-pyridylmethyl)amine) ( tpa ). The complexes [NiII( tpa )(H 2 O)(MeCN)](BF 4) 2 , [NiII( tpa )(NO 3) 2 ], and [NiII( tpa )Cl 2 ] were studied for their ability to electrochemically reduce CO 2. These complexes were compared with the tris-chelate complex [Ni(bpy) 3 ](BF 4) 2 to understand the role of flexible tetradentate ligands containing a pyridinic ring in the electrochemical reduction of CO 2. Spectroelectrochemical experiments and theoretical studies were performed to rationalize the electrochemical reductions occurring and to predict the redox potential and pathway of CO 2 reduction. The electrochemical behavior of Ni(II) complexes with the ligand tris(2-pyridylmethyl)amine) was studied, in order to explore its ability to reduce electrochemically CO 2. Theoretical studies allowed to rationalize where the electrochemical reductions occur and predict redox potential and the pathway of CO 2 reduction. [Display omitted] [ABSTRACT FROM AUTHOR]

• Homogeneous electron transfer rate constant values (ks) between GOD and metal complexes were calculated through (FOWA) from cyclic voltammetry data. • CD spectroscopy reveals no structural changes GOD in the presence of the redox mediators. • Molecular docking studies between GOD and Co(II) complexes and a series of ferrocene derivatives allow to propose a electron transfer model. • Quantitative Structure-Activity Relationship (QSAR) analyses were used to understand electron transfer. In this work, we study the redox mediation of glucose oxidase (GOD) with a series of Co(II) polypyridine complexes [CoIIL 3 ]2+ (L = 5-Nitro-1,10-phenanthroline, 5-Chloro-1,10-phenanthroline, 5-Bromo-1,10-phenanthroline, 1,10-phenanthroline and 5-methyl-1,10-phenanthroline) and Ferrocenecarboxylic acid (Fc-COOH), in order to understand the role of molecular interaction GOD-mediator on homogeneous electron transfer rate constant ( ks ), exploring Marcus cross-relation and tunneling effect model, not reported before. The ks values were calculated through a foot of the wave analysis (FOWA) from cyclic voltammetry data. Circular Dichroism spectroscopy reveals no structural changes in the enzyme in the presence of the redox mediators. The interaction energy between GOD and Co(II) complexes and a series of ferrocene derivatives (FcCOOH, Fc-CH 2 NH(CH 3) 2 , Fc-1,1-CH 3 , Fc-CH CH 2, and Fc) was calculated using DFT and molecular docking. Quantitative Structure-Activity Relationship (QSAR) analyses were explored to rationalize ks values with theoretical calculations. The results allow us to propose that the GOD-mediator interaction, should be considered for a better description of the electron transfer process, useful for potential bioelectronic applications. The redox mediation of (GOD) with a series of Co(II) polypyridine complexes and ferrocene derivatives was studied, to understand the role molecular interaction GOD-mediator on homogeneous electron transfer rate constant ( ks ). Circular Dichroism, DFT and molecular docking studies are reported. Quantitative Structure-Activity Relationship (QSAR) analyses were explored. [Display omitted] [ABSTRACT FROM AUTHOR]