1. The effect of preconditioning strategies on the adsorption of model proteins onto screen-printed carbon electrodesTea Romih, Ivan Konjević, Lea Žibret, Ika Fazarinc, Ajda Beltram, David Majer, Matjaž Finšgar, Samo B. Hočevar, 2022, original scientific article Abstract: The preconditioning and modification of the supporting electrode surface is an essential
step in every biosensor architecture. In particular, when using screen-printed carbon electrodes (SPEs)
as inexpensive and convenient disposable sensor substrates, their somewhat lower electrochemical
(surface) reproducibility might represent a complex hurdle. Herein, we investigated the effect of
selected preconditioning strategies, such as cyclic voltammetric pretreatment, in H2SO4 and H2O2
and plasma pretreatment with a positive and negative glow discharge, which all improved the electrochemical stability of the unmodified SPEs. Furthermore, we studied the influence of preconditioning
strategies on the adsorption kinetics of the two most commonly used building blocks for biosensor
preparation, i.e., bovine serum albumin (BSA) and protein A. We observed an advantageous effect
of all the examined preconditioning strategies for the modification of SPEs with protein A, being
the most effective the negative glow discharge. On the other hand, BSA exhibited a more complex
adsorption behavior, with the negative glow discharge as the only generally beneficial preconditioning strategy providing the highest electrochemical stability. Protein A revealed a more substantial
impact on the electrochemical signal attenuation than BSA considering their same concentrations in
the modification solutions. For both BSA and protein A, we showed that the concentrations of 5 and
10 µg mL−1 already suffice for an electrochemically satisfactorily stable electrode surface after 60 min
of incubation time, except for BSA at the positive-plasma-treated electrode.
Keywords: screen-printed carbon electrode, SPE, electrochemical biosensor, adsorption, bovine serum albumin, protein A, glow discharge
Published in DKUM: 15.05.2025; Views: 0; Downloads: 7
 Full text (1,23 MB)
This document has many files! More... |
2. A HepG2 cell-based biosensor that uses stainless steel electrodes for hepatotoxin detectionMartin Rozman, Zala Štukovnik, Ajda Sušnik, Amirhossein Pakseresht, Matej Hočevar, Damjana Drobne, Urban Bren, 2022, original scientific article Abstract: Humans are frequently exposed to environmental hepatotoxins, which can lead to liver
failure. Biosensors may be the best candidate for the detection of hepatotoxins because of their high
sensitivity and specificity, convenience, time-saving, low cost, and extremely low detection limit. To
investigate suitability of HepG2 cells for biosensor use, different methods of adhesion on stainless
steel surfaces were investigated, with three groups of experiments performed in vitro. Cytotoxicity
assays, which include the resazurin assay, the neutral red assay (NR), and the Coomassie Brilliant Blue
(CBB) assay, were used to determine the viability of HepG2 cells exposed to various concentrations of
aflatoxin B1 (AFB1) and isoniazid (INH) in parallel. The viability of the HepG2 cells on the stainless
steel surface was quantitatively and qualitatively examined with different microscopy techniques. A
simple cell-based electrochemical biosensor was developed by evaluating the viability of the HepG2
cells on the stainless steel surface when exposed to various concentrations of AFB1 and INH by using
electrochemical impedance spectroscopy (EIS). The results showed that HepG2 cells can adhere to the
metal surface and could be used as part of the biosensor to determine simple hepatotoxic samples.
Keywords: HepG2 cell line, impedance biosensor, adhesion, hepatotoxins, stainless steel
Published in DKUM: 10.04.2025; Views: 0; Downloads: 11
Full text (1,87 MB)
This document has many files! More... |
3. 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: 62
Full text (1,56 MB)
This document has many files! More... |
4. 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: 41
Full text (3,14 MB)
This document has many files! More... |
