scholarly journals Advances in Electrochemical Impedance Spectroscopy Detection of Endocrine Disruptors

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6443
Author(s):  
Lucian-Gabriel Zamfir ◽  
Mihaela Puiu ◽  
Camelia Bala
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Endocrine Disruptors ◽  
Electrochemical Impedance ◽  
Early Stage ◽  
Endocrine System ◽  
Detection Methods ◽  
Enzyme Linked Immunosorbent Assay ◽  
Portable Devices ◽  
Wide Range

Endocrine disruptors (EDs) are contaminants that may mimic or interfere with the body’s hormones, hampering the normal functions of the endocrine system in humans and animals. These substances, either natural or man-made, are involved in development, breeding, and immunity, causing a wide range of diseases and disorders. The traditional detection methods such as enzyme linked immunosorbent assay (ELISA) and chromatography are still the golden techniques for EDs detection due to their high sensitivity, robustness, and accuracy. Nevertheless, they have the disadvantage of being expensive and time-consuming, requiring bulky equipment or skilled personnel. On the other hand, early stage detection of EDs on-the-field requires portable devices fulfilling the Affordable, Sensitive, Specific, User-friendly, Rapid and Robust, Equipment free, Deliverable to end users (ASSURED) norms. Electrochemical impedance spectroscopy (EIS)-based sensors can be easily implemented in fully automated, sample-to-answer devices by integrating electrodes in microfluidic chips. The latest achievements on EIS-based sensors are discussed and critically assessed.

scholarly journals Electrochemical Impedance Spectroscopy Characterization of Label-Free Biosensors for the Detection of HER2 in Saliva

Proceedings ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 17
Author(s):  
Imad Abrao Nemeir ◽  
Lynn Mouawad ◽  
Joseph Saab ◽  
Walid Hleihel ◽  
Abdelhamid Errachid ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Ease Of Use ◽  
Detection Methods ◽  
Cancer Type ◽  
Label Free ◽  
Human Epidermal Receptor

Breast cancer is the leading cancer type for women with two million new yearly infections and more than half a million dead worldwide. Human Epidermal Receptor 2 (HER2) is a prominent breast cancer biomarker that indicates aggressive cancer and is often associated with a bad prognosis and low survival rates. However, current detection methods for HER2 are often time-consuming, expensive, and require a high level of expertise. Biosensors are devices that turn biological interaction into a readable electronic signal; they are known for their high specificity and selectivity for low concentration, as well as their low cost and ease of use, thus making them a better alternative to traditional methods. Also, saliva is becoming a better alternative to blood for the detection of biomarkers due to its non-invasive collection in large quantities with simple collection methods with a richness in disease biomarkers including HER2. Thus, this project aims to develop a label-free, low cost, electrochemical biosensor for the detection of HER2 in saliva. This was done by first depositing diazonium salt onto a screen-printed electrode (SPE) through cyclic voltammetry, then immobilizing anti-HER2 antibodies on the activated SPE using 1-ethyl-3-(3-dimethylamino) propyl carbodiimide/N-hydroxysuccinimide. HER2 biomarker concentrations were detected using electrochemical impedance spectroscopy inside a microfluidic system. The biosensor showed a higher linear detection of HER2 (Y = 0.0062X + 0.1066/R2 = 0.9909) in its physiological concentration range of 5 and 40 pg/mL when compared to other interference proteins: Epidermal Growth Factor Receptor (Y = 0.0016X + 0.0188/R2 = 0.8072) and Human Epidermal Receptor 3 (Y = (0.0035X + 0.0225/R2 = 0.1302). The biosensor was then used to detect 10 pg/mL of HER2 concentration in real saliva using the standard addition methods (Y = 0.0118X + 0.1282/R2 = 0.9876).

A Mathematical Model for Her Reaction to Determine Different Pt loads on Pt/C Electrodes

2011 ◽  
Vol 14 (2) ◽  
pp. 107-111 ◽  
Author(s):  
L. Ortega-Chavez ◽  
E. Herrera-Peraza ◽  
Y. Verde-Gomez
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Hydrogen Evolution Reaction ◽  
Electrochemical Impedance ◽  
Precision Measurements ◽  
Metal Electrodes ◽  
Nondestructive Technique ◽  
Wide Range

In the preparation of electrodes Pt / C, one of the highlights is its characterization, particularly the possibility of determining the effective charge of platinum available to carry out a reaction by a nondestructive technique. Electrochemical impedance spectroscopy (EIS) is a technique that provides high precision measurements, producing a stable response without significantly altering the system under study. This paper proposes the use of a hydrogen evolution reaction (HER) mathematical model, validated by experimental data obtained from the implementation of the EIS technique to electrodes with different Platinum loads, in a wide range of frequencies and five different overpotentials. The model takes into account the kinetic, diffusive and adsorption aspects, and also allows to obtain the rate constants for each step of the HER reaction in each of the electrodes used. Although this methodology was used only for Pt/C electrodes suggests a much broader application that extends to any metal electrodes that are capable of evolving hydrogen, with minimal modifications for each particular case.

scholarly journals Property Characterization and Mechanism Analysis of Polyoxometalates-Functionalized PVDF Membranes by Electrochemical Impedance Spectroscopy

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 214
Author(s):  
Lei Yao ◽  
Ziyi Long ◽  
Zhe Chen ◽  
Qisong Cheng ◽  
Yuan Liao ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Polyvinylidene Fluoride ◽  
Electrochemical Impedance ◽  
Early Stage ◽  
Membrane Surface ◽  
Polymeric Membrane ◽  
Intrinsic Properties ◽  
Membrane Matrix ◽  
Pore Structures

Polyoxometalates (POMs) has proved its advantage in constructing high-performance nanocomposite membranes such as catalytic membranes, adsorptive membranes, and forward osmosis membranes. However, it is challenging or tedious to characterize its distribution and effect on the membrane structures due to the equipment resolution limitation, discrete nano-scaled structures of POMs, and limited doping amount compared to the polymeric membrane matrix. In this paper, POMs-functionalized polyvinylidene fluoride (PVDF) membranes were fabricated by phase inversion combined with the sol-gel method, and electrochemical impedance spectroscopy (EIS) was utilized to analyze the nanocomposite membrane intrinsic properties. Through adjusting the additives in the sol-forming process, a set of membranes with varied intrinsic properties were developed accordingly. The wetting degree of the membranes related to the hydrophilic nature of the membrane surfaces had a crucial influence on the impedance measurements at the early stage. Through EIS analysis, it was demonstrated that the amination of the membrane matrix through (3-aminopropyl)trimethoxysilane (APTMS) treatment and the immobilization of POMs through electrostatic attraction would not generate new pore structures into the membrane and only alter the membrane surface roughness and composition. To my knowledge, it is the first time that EIS was utilized to characterize the hydrophilicity of the membranes and pore structures of the POMs-modified membranes. Our findings indicate that EIS can provide valuable information for probing the structures of other nano-materials-incorporated membranes.

scholarly journals Battery State Estimation for Lead-Acid Batteries under Float Charge Conditions by Impedance: Benchmark of Common Detection Methods

2018 ◽  
Vol 8 (8) ◽  
pp. 1308 ◽  
Author(s):  
Julia Badeda ◽  
Monika Kwiecien ◽  
Dominik Schulte ◽  
Dirk Sauer
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Relative Increase ◽  
Detection Methods ◽  
Uninterruptible Power Supply ◽  
Lead Acid Batteries ◽  
Uninterruptible Power ◽  
Eis Measurements ◽  
Lead Acid

Impedance or admittance measurements are a common indicator for the condition of lead-acid batteries in field applications such as uninterruptible power supply (UPS) systems. However, several commercially available measurement units use different techniques to measure and interpret the battery impedance. This paper describes common measurement methods and compares their indication for the state of health (SoH) to those of electrochemical impedance spectroscopy (EIS). For this analysis, two strings consisting each of 24 valve-regulated lead-acid (VRLA) batteries with a rated voltage of 12 V and about 7 Ah capacity were kept under standard UPS conditions in float charge for over 560 days. They were monitored continuously with a LEM Sentinel 2 and went into regular check-ups with impedance measurements by a Hioki BT3554 as well as electrochemical impedance spectroscopy (EIS) measurements with an impedance meter (μEIS). Today it is widely expected that solely the relative increase of the impedance reading is sufficient for the estimation of the available capacity. However, it can be shown that the measured relative increase deviates for different frequencies and therefore the choice of the excitation signal and measurement frequency does make a difference for the calculation of the available capacity. Finally, a method for a more decisive monitoring in field applications is suggested.

scholarly journals Potentiodynamic Electrochemical Impedance Spectroscopy of Polyaniline-Modified Pencil Graphite Electrodes for Selective Detection of Biochemical Trace Elements

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 31
Author(s):  
Adel Yavarinasab ◽  
Mostafa Abedini ◽  
Hamed Tahmooressi ◽  
Sajjad Janfaza ◽  
Nishat Tasnim ◽  
...  
Keyword(s):  
Trace Elements ◽  
Charge Transfer ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Equivalent Circuit ◽  
Electrochemical Impedance ◽  
Graphite Electrodes ◽  
Transfer Resistance ◽  
Wide Range ◽  
Potentiodynamic Electrochemical Impedance Spectroscopy

In this study, we analyzed the application of potentiodynamic electrochemical impedance spectroscopy (PDEIS) for a selective in situ recognition of biological trace elements, i.e., Cr (III), Cu (II), and Fe (III). The electrochemical sensor was developed using the electropolymerization of aniline (Ani) on the surface of the homemade pencil graphite electrodes (PGE) using cyclic voltammetry (CV). The film was overoxidized to diminish the background current. A wide range of potential (V = −0.2 V to 1.0 V) was investigated to study the impedimetric and capacitive behaviour of the PAni/modified PGE. The impedance behaviors of the films were recorded at optimum potentials through electrochemical impedance spectroscopy (EIS) and scrutinized by means of an appropriate equivalent circuit at different voltages and at their corresponding oxidative potentials. The values of the equivalent circuit were used to identify features (charge transfer-resistant and double layer capacitance) that can selectivity distinguish different trace elements with the concentration of 10 μM. The PDEIS spectra represented the highest electron transfer for Cu (II) and Cr (III) in a broad potential range between +0.1 and +0.4 V while the potential V = +0.2 V showed the lowest charge transfer resistance for Fe (III). The results of this paper showed the capability of PDEIS as a complementary tool for conventional CV and EIS measurement for metallic ion sensing.

scholarly journals Towards robotizing the processes of testing lithium-ion batteries

2021 ◽  
pp. 095965182199859
Author(s):  
Alireza Rastegarpanah ◽  
Mohamed Ahmeid ◽  
Naresh Marturi ◽  
Pierrot S Attidekou ◽  
Muhammad Musbahu ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Visual Servoing ◽  
Electrochemical Impedance ◽  
Impedance Control ◽  
Form Factors ◽  
Lithium Ion ◽  
Battery Cell ◽  
Wide Range ◽  
Battery Module

To boost the circular economy of the electric vehicle battery industry, an accurate assessment of the state of health of retired batteries is essential to assign them an appropriate value in the post automotive market and material degradation before recycling. In practice, the advanced battery testing techniques are usually limited to laboratory benches at the battery cell level and hardly used in the industrial environment at the battery module or pack level. This necessitates developing battery recycling facilities that can handle the assessment and testing undertakings for many batteries with different form factors. Towards this goal, for the first time, this article proposes proof of concept to automate the process of collecting the impedance data from a retired 24kWh Nissan LEAF battery module. The procedure entails the development of robot end-of-arm tooling that was connected to a Potentiostat. In this study, the robot was guided towards a fixed battery module using visual servoing technique, and then impedance control system was applied to create compliance between the end-of-arm tooling and the battery terminals. Moreover, an alarm system was designed and mounted on the robot’s wrist to check the connectivity between a Potentiostat and the battery terminals. Subsequently, the electrochemical impedance spectroscopy test was run over a wide range of frequencies at a 5% state of charge. The electrochemical impedance spectroscopy data obtained from the automated test is validated by means of the three criteria (linearity, causality and stability) and compared with manually collected measurements under the same conditions. Results suggested the proposed automated configuration can accurately accomplish the electrochemical impedance spectroscopy test at the battery module level with no human intervention, which ensures safety and allows this advanced testing technique to be adopted in grading retired battery modules.

scholarly journals Evaluation of Temperature Influence on Electrochemical Processes Occurring in a Lithium-Ion Supercapacitor with the Use of Dynamic Electrochemical Impedance Spectroscopy

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3807
Author(s):  
Michal Mielniczek ◽  
Ewa Janicka ◽  
Lukasz Gawel ◽  
Kazimierz Darowicki
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Impedance Analysis ◽  
Electrochemical Processes ◽  
Impedance Characteristics ◽  
Lithium Ion Capacitor ◽  
Wide Range ◽  
Dynamic Electrochemical Impedance Spectroscopy

In order to obtain the full impedance characteristics of a lithium-ion capacitor as a function of temperature, the authors proposed the use of dynamic electrochemical impedance spectroscopy. Impedance tests were carried out under wide range of dynamic temperature changes for lithium-ion supercapacitors. Significant differences in electrochemical processes were observed as a result of working temperature. Moreover, the quality of fitting of the equivalent circuits most frequently used in impedance analysis of lithium-ion capacitors was discussed. The proposed methodology allows for a comprehensive characterization of the performance of these devices and provides key information for their optimization in wide range of operations.

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