Biophysical and electrochemical studies of protein-nucleic acid interactions

This review is devoted to biophysical and electrochemical methods used for studying protein-nucleic acid (NA) interactions. The importance of NA structure and protein-NA recognition for essential cellular processes, such as replication or transcription, is discussed to provide background for description of a range of biophysical chemistry methods that are applied to study a wide scope of protein-DNA and protein-RNA complexes. These techniques employ different detection principles with specific advantages and limitations and are often combined as mutually complementary approaches to provide a complete description of the interactions. Electrochemical methods have proven to be of great utility in such studies because they provide sensitive measurements and can be combined with other approaches that facilitate the protein-NA interactions. Recent applications of electrochemical methods in studies of protein-NA interactions are discussed in detail

Electrodeposition of silver amalgam particles on ITO – Towards novel electrode material

© 2017 Elsevier B.V. Silver solid amalgam represents up to now the most suitable alternative electrode material to metallic mercury in electroanalytical chemistry. Controlled electrodeposition of variable (sub)micrometer-sized silver amalgam particles (AgAP) on the surface of transparent indium-tin oxide (ITO) electrode from an electrolyte containing Ag+ and Hg2+ ions is reported here, as a novel perspective method suitable for preparation of nano-structured silver amalgam electrode material. Elemental analysis of the composition and morphology of the AgAP decorating the ITO was studied by scanning electron microscopy including energy-disperse X-ray spectroscopy and by image processing software. Particle composition, size, and surface coverage are controllable by selection of the Ag+/Hg2+ ratio in the electrodeposition solution and by setting of individual parameters of applied double pulsed/potential chronoamperometry. Applicable potential window of thus prepared ITO-AgAP electrode was found to be within +0.2 to −1.0 V in 0.2 acetate buffer pH 5.0. Utilized voltammetric and chronoamperometric methods revealed significant enhancement in electrochemical reducibility of selected model organic nitro-compound (shift of the peak potential about 300 mV to more positive potentials). Its further employment in UV/Vis spectroelectrochemical cell provided information about number of consumed electrons and kinetic characteristics. Furthermore preferential adsorption of calf thymus DNA at AgAP than ITO was observed by fluorescence microscopy indicating its potential applicability in (bio-)spectroelectrochemical methods. Further advantages and potential applications are also proposed and discussed

Lightweight ITO electrodes decorated with gold nanostructures for electrochemical applications

Gold nanostructures were fabricated on a transparent indium tin oxide (ITO) coated PET substrate by an electrodeposition technique from a potassium gold (III) chloride solution for two different types of applications. It was found that the optical transparency of lightweight ITO electrodes could be maintained by depositing isolated gold nanostructures while opening up the use of these electrodes for inner sphere electron reactions, such as hydroquinone oxidation, which are not possible at ITO electrodes. For practical applications the adhesion of gold to the ITO electrode was improved by modifying the ITO surface with 3-mercaptopropyl-trimethoxysilane (MPS). Compared to Au/ITO, the Au/MPS/ITO electrode showed vastly improved electrochemical activity toward various electron transfer reactions when subjected to mechanical stress. The biosensing properties of the Au/MPS/ITO electrode was also investigated by studying the detection of immobilized DNA on the Au/MPS/ITO electrode via electrochemical impedance spectroscopy (EIS).</p