1. Recent developments in electrochemical-impedimetric biosensors for virus detectionZala Štukovnik, Urban Bren, 2022, review article Abstract: Viruses, including influenza viruses, MERS-CoV (Middle East respiratory syndrome coronavirus), SARS-CoV (severe acute respiratory syndrome coronavirus), HAV (Hepatitis A virus), HBV (Hepatitis B virus), HCV (Hepatitis C virus), HIV (human immunodeficiency virus), EBOV (Ebola virus), ZIKV (Zika virus), and most recently SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), are responsible for many diseases that result in hundreds of thousands of deaths yearly. The ongoing outbreak of the COVID-19 disease has raised a global concern and intensified research on the detection of viruses and virus-related diseases. Novel methods for the sensitive, rapid, and on-site detection of pathogens, such as the recent SARS-CoV-2, are critical for diagnosing and treating infectious diseases before they spread and affect human health worldwide. In this sense, electrochemical impedimetric biosensors could be applied for virus detection on a large scale. This review focuses on the recent developments in electrochemical-impedimetric biosensors for the detection of viruses. Keywords: electrochemical impedance spectroscopy, impedimetric biosensor, genosensor, aptasensor, immunosensor, virus detection, SARS-CoV-2, HIV, influenza virus, hepatitis virus Published in DKUM: 05.12.2024; Views: 0; Downloads: 7 Full text (1,56 MB) This document has many files! More... |
2. Nanomaterials and their recent applications in impedimetric biosensingZala Štukovnik, Regina Fuchs-Godec, Urban Bren, 2023, review article Abstract: Impedimetric biosensors measure changes in the electrical impedance due to a biochemical process, typically the binding of a biomolecule to a bioreceptor on the sensor surface. Nanomaterials can be employed to modify the biosensor's surface to increase the surface area available for biorecognition events, thereby improving the sensitivity and detection limits of the biosensor. Various nanomaterials, such as carbon nanotubes, carbon nanofibers, quantum dots, metal nanoparticles, and graphene oxide nanoparticles, have been investigated for impedimetric biosensors. These nanomaterials have yielded promising results in improving sensitivity, selectivity, and overall biosensor performance. Hence, they offer a wide range of possibilities for developing advanced biosensing platforms that can be employed in various fields, including healthcare, environmental monitoring, and food safety. This review focuses on the recent developments in nanoparticle-functionalized electrochemical-impedimetric biosensors. Keywords: impedimetric biosensor, electrochemical impedance spectroscopy, nanomaterials, metal nanoparticles, carbon nanofibers, carbon nanotubes, graphene oxide, quantum dots Published in DKUM: 12.02.2024; Views: 6175; Downloads: 24 Full text (3,14 MB) This document has many files! More... |
3. Electrochemical and surface analysis of 2-phenylimidazole adsorbed on copper from chloride solutionMatjaž Finšgar, Klodian Xhanari, 2018, original scientific article Abstract: The electroanalytical and surface characterization of copper immersed in 3 wt.% NaCl solution containing 1 mM of 2-phenylimidazole (2PhI) is presented. It was proven that 2PhI can be employed as corrosion inhibitor for copper using various electrochemical analyses, such as cyclic voltammetry, chronopotentiometry, electrochemical impedance spectroscopy, and potentiodynamic curve measurements. The adsorption of 2PhI on copper was further analyzed by 3D-profilometry, attenuated total reflectance Fourier transform infrared spectroscopy, contact angle measurements, and scanning electron microscopy equipped with an energy dispersive X-ray spectrometer. This system was therefore comprehensively described by various analytical approaches. Keywords: corrosion inhibitor, copper, electrochemical impedance spectroscopy, EIS, cyclic voltammetry, attenuated total reflectance Fourier transform infrared, ATR-FTIR Published in DKUM: 17.01.2019; Views: 2084; Downloads: 392 Full text (5,88 MB) This document has many files! More... |
4. Substitution of the constant phase element by Warburg impedance for protective coatingsSaša Skale, Valter Doleček, Mojca Slemnik, 2007, original scientific article Abstract: This paper proposes an alternative model for fitting electrochemical impedance spectra of protective coatings. It describes broadening of the semicircle in the complex plane, in the absence of corrosion reactions. In addition the infinite Warburg impedance circuit element is represented, which bridges existing parallel elements of the plate capacitor and resistor of a classical equivalent electrical circuit. The Warburg impedance element is the result of the Fick's second law on partial differential equation solution. The proposed model and, for comparison the model with the CPE element, are used on our epoxy protective system to describe EIS measurements. The proposed model shows a better quality of fitting for our EIS data in comparison to the model with CPE. Keywords: metal-coatings, electrochemical impedance spectroscopy, Nyquist charts, constant phase element, Warburg impedance Published in DKUM: 01.06.2012; Views: 2597; Downloads: 115 Link to full text |
5. Electrochemical impedance studies of corrosion protected surfaces covered by epoxy polyamide coating systemsSaša Skale, Valter Doleček, Mojca Slemnik, 2008, original scientific article Abstract: Electrochemical impedance spectroscopy (EIS) was used to study the corrosion behavior of different types of commercial quality epoxy polyamide dry coatingson mild steel, with thickness between 150 and 250 ▫$/mu$▫m, which were previously weather accelerated in a wet chamber. The following data were established on the basis of impedance curves and corresponding equivalent circuits: the coating capacity that relates to the coating dimension, the pore resistance that represents conductive paths through the pores, and Warburg coefficients, which are the measure of ion diffusion through the coating. EIS data were compared with a criterion in the European standard, and samples were classified on the basis of their quality, also receiving a final ranking by summing-up all the individual rankings. Suggestions have been made, namely that the use of anticorrosive active pigments is obsolete, when the thickness of the coatings exceeds 200 ▫$/mu$▫m. Keywords: electrochemical impedance spectroscopy, metal-coatings, epoxy polyamide coatings, weathering, ISO 12944 Published in DKUM: 31.05.2012; Views: 3119; Downloads: 106 Link to full text |
6. An impedance study of two types of stainless steel in Ringer physiological solution containing complexing agentsMojca Slemnik, Ingrid Milošev, 2006, original scientific article Abstract: The effect of complexing agents EDTA and citric acid on the electrochemical behaviour of AISI 304 and orthopaedic stainless steels in Ringer physiological solution was investigated by potentiodynamic polarization method and electrochemical impedance spectroscopy (EIS). The content of Mo has a pronounced effect on the corrosion resistance, as evident by the broader passive range of the orthopaedic stainless steel containing Mo. The addition of complexing agents induces significant changes in polarization and impedance characteristics, i.e., the shift of corrosion and breakdown potentials in a more negative direction, an increase in current density, and a significant decrease in charge transfer resistance. The results were interpreted by the formation of soluble complexes of metal ions with chelating agents, especially EDTA, which suppressed the formation of the outer Fe(III) layer of the passive film. The impact of complexing agent on the electrochemical parameters was found to be related to its concentration in electrolyte and the stability constant of the complex formed with the related metal ion. Keywords: resistance, corrosion resistance, stainless steel, orthopedy, potentiodynamic polarization emthod, electrochemical impedance spectroscopy Published in DKUM: 31.05.2012; Views: 2038; Downloads: 118 Link to full text |
7. Modelling and parameter comparison of equivalent circuits on the basis of impedance measurements of stainless steelsMojca Slemnik, 2006, original scientific article Abstract: In our former work [1] we have discussed the impedance of differently heat treated steels X20Cr13 in 0.1 M H2SO4, undergoing an active passive transition. Impedance spectra were interpreted in terms of a model by Armstrong [2, 3], describing the electrochemical reaction at interfaces with adsorbed intermediates. The present work was performed in order to study this phenomenon in more detail, with computer simulations of a new created and more convenient equivalent circuit in comparison with the former model. Computer simulations of equivalent circuits were also made in the region of passivity which was also continuation of our earlier work [4]. In this sense the entire study for these steels was completed by collating distinctive parameter values, demonstrating electrochemical characteristics of steel X20Cr13, undergoing different heat treatments in the active-passive and passive region. Keywords: electrochemical impedance spectroscopy, equivalent circuits, stainless steel, heat treatment of steel Published in DKUM: 30.05.2012; Views: 2359; Downloads: 98 Link to full text |