Electrochemical Detection of Prostate Cancer Biomarker PCA3 Using Specific RNA-Based Aptamer Labelled with Ferrocene

This paper reports on a feasibility study of electrochemical in-vitro detection of prostate cancer biomarker PCA3 (prostate cancer antigen 3) in direct assay with specific RNA aptamer labelled with a redox group (ferrocene) and immobilized on a screen-printed gold electrode surface. The cyclic voltammograms and electrochemical impedance spectroscopy methods yield encouraging results on the detection of PCA3 in a range of concentrations from 1 μg/mL down to 0.1 ng/mL in buffer solutions. Both anodic and cathodic current values in cyclic voltammograms measurements and charge transfer resistance values in electrochemical impedance spectroscopy experiments correlate with the PCA3 concentration in the sample. Kinetics studies of the binding of the PCA3 to our aptamer demonstrated high specificity of the reaction with a characteristic affinity constant of approximately 4·10−10 molar. The results of this work provide a background for the future development of novel, highly sensitive and cost-effective diagnostic methodologies for prostate cancer detection.

Download Full-text

Changes in the interfacial charge-transfer resistance of Mg metal electrodes, measured by dynamic electrochemical impedance spectroscopy

Electrochemistry Communications ◽

10.1016/j.elecom.2021.106952 ◽

2021 ◽

Vol 124 ◽

pp. 106952

Author(s):

Ran Attias ◽

Ben Dlugatch ◽

Munseok S. Chae ◽

Yosef Goffer ◽

Doron Aurbach

Keyword(s):

Charge Transfer ◽

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Electrochemical Impedance ◽

Charge Transfer Resistance ◽

Metal Electrodes ◽

Transfer Resistance ◽

Interfacial Charge Transfer ◽

Dynamic Electrochemical Impedance Spectroscopy ◽

Interfacial Charge

Download Full-text

Protection of Carbon Steel Rebars by Epoxy Coating with Smart Environmentally Friendly Microcapsules

Coatings ◽

10.3390/coatings11020113 ◽

2021 ◽

Vol 11 (2) ◽

pp. 113

Author(s):

Jacob Ress ◽

Ulises Martin ◽

Juan Bosch ◽

David M. Bastidas

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Corrosion Protection ◽

Corrosion Potential ◽

Electrochemical Impedance ◽

Pore Solution ◽

Control Sample ◽

Chloride Ions ◽

Epoxy Coating ◽

Transfer Resistance

The protection of mild steel by modified epoxy coating containing colophony microencapsulated corrosion inhibitors was investigated in this study. The corrosion behavior of these epoxy coatings containing colophony microcapsules was studied by electrochemical analysis using cyclic potentiodynamic polarization and electrochemical impedance spectroscopy. The microcapsule coating showed decreased corrosion current densities of 2.75 × 10−8 and 3.21 × 10−8 A/cm2 along with corrosion potential values of 0.349 and 0.392 VSCE for simulated concrete pore solution and deionized water with 3.5 wt.% NaCl, respectively, indicating improved corrosion protection in both alkaline and neutral pH. Electrochemical impedance spectroscopy analysis also showed charge transfer resistance values over one order of magnitude higher than the control sample, corroborating the electrochemical corrosion potential and current density testing results. Overall, the use of colophony microcapsules showed improved corrosion protection in simulated concrete pore solution and DI water solutions containing chloride ions.

Download Full-text

Deciphering the Disaggregation Mechanism of Amyloid Beta Aggregate by 4-(2-Hydroxyethyl)-1-Piperazinepropanesulfonic Acid Using Electrochemical Impedance Spectroscopy

Sensors ◽

10.3390/s21030788 ◽

2021 ◽

Vol 21 (3) ◽

pp. 788

Author(s):

Hien T. Ngoc Le ◽

Sungbo Cho

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Electrochemical Impedance ◽

Specific Binding ◽

Amyloid Β ◽

Electrochemical Measurement ◽

Charge Transfer Resistance ◽

Chemical Agent ◽

Transfer Resistance ◽

K Value

Aggregation of amyloid-β (aβ) peptides into toxic oligomers, fibrils, and plaques is central in the molecular pathogenesis of Alzheimer’s disease (AD) and is the primary focus of AD diagnostics. Disaggregation or elimination of toxic aβ aggregates in patients is important for delaying the progression of neurodegenerative disorders in AD. Recently, 4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid (EPPS) was introduced as a chemical agent that binds with toxic aβ aggregates and transforms them into monomers to reduce the negative effects of aβ aggregates in the brain. However, the mechanism of aβ disaggregation by EPPS has not yet been completely clarified. In this study, an electrochemical impedimetric immunosensor for aβ diagnostics was developed by immobilizing a specific anti-amyloid-β (aβ) antibody onto a self-assembled monolayer functionalized with a new interdigitated chain-shaped electrode (anti-aβ/SAM/ICE). To investigate the ability of EPPS in recognizing AD by extricating aβ aggregation, commercially available aβ aggregates (aβagg) were used. Electrochemical impedance spectroscopy was used to probe the changes in charge transfer resistance (Rct) of the immunosensor after the specific binding of biosensor with aβagg. The subsequent incubation of the aβagg complex with a specific concentration of EPPS at different time intervals divulged AD progression. The decline in the Rct of the immunosensor started at 10 min of EPPS incubation and continued to decrease gradually from 20 min, indicating that the accumulation of aβagg on the surface of the anti-aβ/SAM/ICE sensor has been extricated. Here, the kinetic disaggregation rate k value of aβagg was found to be 0.038. This innovative study using electrochemical measurement to investigate the mechanism of aβagg disaggregation by EPPS could provide a new perspective in monitoring the disaggregation periods of aβagg from oligomeric to monomeric form, and then support for the prediction and handling AD symptoms at different stages after treatment by a drug, EPPS.

Download Full-text

Thin film-modified electrodes: a model for the charge transfer resistance in electrochemical impedance spectroscopy

Journal of Solid State Electrochemistry ◽

10.1007/s10008-014-2662-1 ◽

2014 ◽

Vol 18 (12) ◽

pp. 3239-3243 ◽

Cited By ~ 9

Author(s):

Shaltiel Eloul ◽

Christopher Batchelor-McAuley ◽

Richard G. Compton

Keyword(s):

Thin Film ◽

Charge Transfer ◽

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Electrochemical Impedance ◽

Modified Electrodes ◽

Charge Transfer Resistance ◽

Transfer Resistance

Download Full-text

Investigation of Temperature and Aging Effects in Nanostructured Dye Solar Cells Studied by Electrochemical Impedance Spectroscopy

International Journal of Photoenergy ◽

10.1155/2009/786429 ◽

2009 ◽

Vol 2009 ◽

pp. 1-15 ◽

Cited By ~ 14

Author(s):

Minna Toivola ◽

Janne Halme ◽

Lauri Peltokorpi ◽

Peter Lund

Keyword(s):

Solar Cells ◽

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Electrochemical Impedance ◽

Charge Transfer Resistance ◽

Aging Effects ◽

Transfer Resistance ◽

Deterioration Rate ◽

Dye Solar Cells ◽

Effects Of Aging

Effects of aging and cyclically varying temperature on the electrical parameters of dye solar cells were analyzed with electrochemical impedance spectroscopy. Photoelectrode total resistance increased as a function of time due to increasing electron transport resistance in theTiO2film. On the other hand, photoelectrode recombination resistance was generally larger, electron lifetimes in theTiO2were film longer, and charge transfer resistance on the counter electrode was smaller after the temperature treatments than before them. These effects correlated with the slower deterioration rate of the temperature-treated cells, in comparison to the reference cells.

Download Full-text

Analysis of Electrochemical Impedance Spectroscopy Results and Ion Release In Vitro of Si+ Ion Implanted Medical 316 LVM Steel

ECS Meeting Abstracts ◽

10.1149/ma2012-02/20/2141 ◽

2012 ◽

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Electrochemical Impedance ◽

Ion Release ◽

Release In Vitro ◽

Ion Implanted

Download Full-text

Yeast Propagation Control: Low Frequency Electrochemical Impedance Spectroscopy as an Alternative for Cell Counting Chambers in Brewery Applications

Chemosensors ◽

10.3390/chemosensors8020027 ◽

2020 ◽

Vol 8 (2) ◽

pp. 27

Author(s):

Georg Christoph Brunauer ◽

Oliver Spadiut ◽

Alfred Gruber ◽

Christoph Slouka

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Pathogen Detection ◽

Electrochemical Impedance ◽

Low Frequency ◽

Charge Transfer Resistance ◽

Cell Counting ◽

Delayed Response ◽

Transfer Resistance ◽

Cell Counts

Electrochemical impedance spectroscopy is a powerful tool in life science for cell and pathogen detection, as well as for cell counting. The measurement principles and techniques using impedance spectroscopy are highly diverse. Differences can be found in used frequency range (β or α regime), analyzed quantities, like charge transfer resistance, dielectric permittivity of double layer capacitance and in off- or online usage. In recent contributions, applications of low-frequency impedance spectroscopy in the α regime were tested for determination of cell counts and metabolic burden in Escherichia coli and Saccharomyces cerevisiae. The established easy to use methods showed reasonable potential in the lab scale, especially for S. cerevisiae. However, until now, measurements for cell counts in food science are generally based on Thoma cell counting chambers. These microscopic cell counting methods decelerate an easy and quick prediction of yeast viability, as they are labor intensive and result in a time delayed response signal. In this contribution we tested our developed method using low frequency impedance spectroscopy locally at an industrial brewery propagation site and compared results to classic cell counting procedures.

Download Full-text

Electrochemical Impedance Spectroscopy on the Performance Degradation of LiFePO4/Graphite Lithium-Ion Battery Due to Charge-Discharge Cycling under Different C-Rates

Energies ◽

10.3390/en12234507 ◽

2019 ◽

Vol 12 (23) ◽

pp. 4507 ◽

Cited By ~ 11

Author(s):

Yusuke Abe ◽

Natsuki Hori ◽

Seiji Kumagai

Keyword(s):

Charge Transfer ◽

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Electrochemical Impedance ◽

Specific Capacity ◽

Lithium Ion ◽

Performance Degradation ◽

Charge Transfer Resistance ◽

Transfer Resistance ◽

Charge Discharge

Lithium-ion batteries (LIBs) using a LiFePO4 cathode and graphite anode were assembled in coin cell form and subjected to 1000 charge-discharge cycles at 1, 2, and 5 C at 25 °C. The performance degradation of the LIB cells under different C-rates was analyzed by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy. The most severe degradation occurred at 2 C while degradation was mitigated at the highest C-rate of 5 C. EIS data of the equivalent circuit model provided information on the changes in the internal resistance. The charge-transfer resistance within all the cells increased after the cycle test, with the cell cycled at 2 C presenting the greatest increment in the charge-transfer resistance. Agglomerates were observed on the graphite anodes of the cells cycled at 2 and 5 C; these were more abundantly produced in the former cell. The lower degradation of the cell cycled at 5 C was attributed to the lowered capacity utilization of the anode. The larger cell voltage drop caused by the increased C-rate reduced the electrode potential variation allocated to the net electrochemical reactions, contributing to the charge-discharge specific capacity of the cells.

Download Full-text

In Vitro Evaluation of Degradation of Biodegradable Silane Based Coating on Mg-Zn-Ca Alloy in a Physiological Environment

Materials Science Forum ◽

10.4028/www.scientific.net/msf.765.803 ◽

2013 ◽

Vol 765 ◽

pp. 803-807

Author(s):

Gaur Swati ◽

Anand Sawroop Khanna ◽

Raghuvir Kumar Singh Raman

Keyword(s):

Corrosion Resistance ◽

Electrochemical Impedance Spectroscopy ◽

Magnesium Alloy ◽

Impedance Spectroscopy ◽

Body Fluid ◽

Degradation Rate ◽

Electrochemical Impedance ◽

Silane Coating ◽

Corrosion Barrier

In the present study, combinations of a phosphonato silane with a precursor, Methyltriethoxy silane (MTEOS) in various ratios were applied onto the alloy Mg-6Zn-Ca. The corrosion resistance of the coated and uncoated specimens in a modified simulated body fluid (m-SBF) was characterized by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Results suggest that the silane coating significantly decreases the degradation rate of the magnesium alloy, indicating its potential to be used as a corrosion barrier for magnesium alloy temporary implants.

Download Full-text