Nanotextured Material for Applications in CSF Sample Screening and Characterization

2012 ◽  
Vol 1466 ◽  
Author(s):  
Krishna Vattipalli ◽  
Savindra Brandigampala ◽  
Claire McGraw ◽  
Gaurav Chatterjee ◽  
Srinath Kasturirangan ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Neurodegenerative Disease ◽  
Double Layer ◽  
Electrical Double Layer ◽  
Protein Misfolding ◽  
Electrochemical Impedance ◽  
Great Promise ◽  
Parkinson’S Diseases ◽  
Specific Association ◽  
High Degree

ABSTRACTNeurodegenerative disease is primarily characterized by protein misfolding and the resultant protein aggregation. Presence of soluble oligomeric aggregates of proteins including various Aβ and α-syn aggregate species can be correlated to the onset and progression of many neurodegenerative diseases. The ability to detect protein misfolding requires the design of a diagnostics assay the will enable molecular level probing. The use of nanoporous ceramic templates enables size based immobilization of the target proteins and by leveraging the principle of “macromolecular crowding” protein association can be mapped with a high degree of resolution. By tailoring the surface functionalization within nanoporous ceramic templates, macromolecular immobilization can be selectively controlled, which in turn significantly enhances the perturbation to the electrical double layer/. The changes to the electrical double layer are measured with a high degree of sensitivity through impedance spectroscopy.Pre symptomatic diagnosis and distinction between Alzheimer’s and Parkinson’s diseases can be achieved by the specific detection and quantification of levels of each of these different toxic protein species in cerebrospinal fluid (CSF). Detection using highly selective morphology specific reagents in conjunction with the ultrasensitive nanoporous electronic biosensor showed the presence of different protein morphologies in human CSF samples. Detection is primarily achieved by identifying the specific association of the protein with its receptor using electrochemical impedance spectroscopy. Furthermore, we show that these morphology specific reagents can readily classify between post-mortem CSF samples from AD, PD and cognitively normal sources. These studies suggest that detection of specific oligomeric aggregate species holds great promise as sensitive biomarkers for neurodegenerative disease.

Nanomonitor Technology for Glycosylation Analysis

2009 ◽  
Vol 1236 ◽  
Author(s):  
Gaurav Chatterjee ◽  
Manish Bothara ◽  
Srivatsa Aithal ◽  
Vinay J Nagraj ◽  
Peter Wiktor ◽  
...  
Keyword(s):  
Double Layer ◽  
Electrical Double Layer ◽  
Printed Circuit Board ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Protein Glycosylation ◽  
Circuit Board ◽  
Biological Macromolecules ◽  
Label Free ◽  
Alumina Membrane

AbstractChanges in protein glycosylation have great potential as markers for the early diagnosis of cancer and other diseases. The current analytical tools for the analysis of glycan structures need expensive instrumentation, advanced expertise, is time consuming and therefore not practical for routine screening of glycan biomarkers from human samples in a clinical setting.We are developing a novel ultrasensitive diagnostic platform called ‘NanoMonitor’ to enable rapid label-free glycosylation analysis. The technology is based on electrochemical impedance spectroscopy where capacitance changes are measured at the electrical double layer interface as a result of interaction of two molecules.The NanoMonitor platform consists of a printed circuit board with array of electrodes forming multiple sensor spots. Each sensor spot is overlaid with a nanoporous alumina membrane that forms a high density of nanowells. Lectins, proteins that bind to and recognize specific glycan structures, are conjugated to the surface of nanowells. When specific glycoproteins from a test sample bind to lectins in the nanowells, it produces a perturbation to the electrical double layer at the solid/liquid interface at the base of each nanowell. This perturbation results in a change in the impedance of the double layer which is dominated by the capacitance changes within the electrical double layer.The nanoscale confinement or crowding of biological macromolecules within the nanowells is likely to enhance signals from the interaction of glycoproteins with the lectins leading to a high sensitivity of detection with the NanoMonitor as compared to other electrochemical techniques.Using a panel of lectins, we were able to detect subtle changes in the glycosylation of fetuin protein as well as differentiate glycoproteins from normal versus cancerous cells. Our results indicate that NanoMonitor can be used as a cost-effective miniature electronic biosensor for the detection of glycan biomarkers.

Modeling electrical double-layer effects for microfluidic impedance spectroscopy from 100 kHz to 110 GHz

Lab on a Chip ◽  
2017 ◽  
Vol 17 (15) ◽  
pp. 2674-2681 ◽  
Author(s):  
Charles A. E. Little ◽  
Nathan D. Orloff ◽  
Isaac E. Hanemann ◽  
Christian J. Long ◽  
Victor M. Bright ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Double Layer ◽  
Electrical Double Layer ◽  
Microfluidic Channels ◽  
Frequency Range ◽  
Broad Frequency Range ◽  
On Chip ◽  
Saline Solutions

On-chip microwave calibrations are used to characterize the electrical-double layer response for saline solutions in microfluidic channels over an extremely broad frequency range.

scholarly journals Viability of Activated Carbon Derived from Polystyrene Sulphonate Beads as Electrical Double Layer Capacitors

2021 ◽  
Vol 7 (4) ◽  
pp. 82
Author(s):  
Gbenro Babajide Folaranmi ◽  
Anthony Ekennia ◽  
Nkiruka Chidiebere Ani ◽  
Richard Chukwuemeka Ehiri
Keyword(s):  
Activated Carbon ◽  
Double Layer ◽  
Electrical Double Layer ◽  
Electrochemical Impedance ◽  
Carbon Sphere ◽  
Potential Candidate ◽  
Carbon Spheres ◽  
Transfer Resistance ◽  
X Ray ◽  
Polystyrene Sulphonate

In this paper, a commercial polymeric resin precursor (polystyrene sulphonate beads) was used as a source of carbon spheres. The resin was pyrolyzed at different temperatures (700, 800, and 900 °C) and the resulting carbons were analyzed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). From the result of EIS, carbon spheres obtained at 700 °C (CS−700) have the least ohmnic resistance and highest capacitance. In furtherance, the resin was chemically activated with iron (III) chloride FeCl3·6H2O at different concentration (0.1 M, 0.3 M, and 0.5 M) and pyrolyzed at 700 °C to obtain activated carbon sphere namely (ACS 700−0.1, ACS 700−0.3, and ACS 700−0.5) in which the last digit of the samples denotes the concentration of FeCl3. Scanning electron microscope (SEM) showed that the carbon is of spherical shape; X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and X-ray photon electron spectroscopy (XPS) revealed successful introduction of Fe on the surface of the carbon. Out of all the activated carbon spheres, ACS 700−0.1 exhibited highest double layer capacitance of 9 µF cm−2 and lowest charge transfer resistance of 3.33 KΩ·cm2. This method shows that carbon spheres obtained from a polymeric source can be easily improved by simple resin modification and the carbon could be a potential candidate for an electrical double layer capacitor

Substituted phosphonium cation based electrolytes for nonaqueous electrical double-layer capacitors

2010 ◽  
Vol 25 (8) ◽  
pp. 1447-1450 ◽  
Author(s):  
H. Kurig ◽  
A. Jänes ◽  
E. Lust
Keyword(s):  
Double Layer ◽  
Electrical Double Layer ◽  
Electrochemical Impedance ◽  
Cell Voltage ◽  
Constant Current ◽  
Electrochemical Characteristics ◽  
Double Layer Capacitor ◽  
Constant Current Charging ◽  
Double Layer Capacitors ◽  
Carbide Derived Carbon

Tetrakis(diethylamino)phosphonium tetrafluoroborate (TDENPBF4), tetrakis(diethylamino)phosphonium hexafluorophosphate (TDENPPF6), and tetrakis(dimethylamino)phosphonium tetrafluoroborate (TDMNPBF4) in acetonitrile (AN) have been studied as electrical double-layer capacitor electrolytes in a two-electrode test cell using titanium carbide derived carbon, C(TiC), as an electrode material. Electrochemical characteristics for C(TiC)|1 M TDENPBF4 + AN, C(TiC)|1 M TDENPPF6 + AN, and C(TiC)|1 M TDMNPBF4 + AN interfaces have been obtained by cyclic voltammetry, constant current charging/discharging, and electrochemical impedance spectroscopy. High-capacitance (85 °F/g) and gravimetric power (269 kW/kg) have been achieved at cell voltage 3.2 V. Data obtained have been compared with results published previously.

scholarly journals Characterization of Molecular Spacer-Functionalized Nanostructured Carbons for Electrical Energy Storage Supercapacitor Materials

2020 ◽  
Vol 6 (4) ◽  
pp. 66
Author(s):  
Justin Zuczek ◽  
Matthew Bonfield ◽  
Nesreen Elathram ◽  
William R. Hixson ◽  
Terawit Kongruengkit ◽  
...  
Keyword(s):  
Energy Storage ◽  
Double Layer ◽  
Electrical Double Layer ◽  
Electrostatic Interactions ◽  
Electrochemical Impedance ◽  
Electrical Characterization ◽  
Electrical Energy ◽  
Accessible Surface Area ◽  
Coordination Complexes ◽  
Nanostructured Carbons

The use of molecular spacers between Carbon Nanotubes (CNTs) has been shown to increase the ion-accessible surface area for use in supercapacitor materials. Maintaining porosity and electrical conductivity is important for maximizing capacitance, energy storage, and power. Two reported novel coordination complexes have shown exceptional Faradaic charge transfer and binding capabilities to prevent CNT aggregation. Dispersion stability measurements show less aggregation of HiPco Single Walled CNTs (SWCNTs) compared to other chirality and multilayered nanotubes. Cu2FcOH binds weakly to CNTs compared +2Zn2 and +2Ru2 due to Columbic electrostatic interactions, which is favorable because it does not collapse the electrical double layer as strongly as +2Zn2 or +2Ru2. Adsorption isotherms and a full characterization (1H NMR, ATR FT-IR, UV-Vis, CV) of these novel complexes are presented. Electrical characterization using CV, charge discharge, and electrochemical impedance spectroscopy and the supercapacitor performance of functionalized thin film electrodes are presented as a function of spacer properties and nanostructured carbon tube diameter. This study uses rigid, earth-abundant coordination complexes that bind to and intercalate between SWCNTs. These functionalized nanostructured carbons are then used to make electrodes for electrical double layer supercapacitors. A complete description of the synthesis, characterization, and processing of these materials is described.

Electrochemical impedance spectroscopy study of CuO and Cu coating systems

2014 ◽  
Vol 43 (6) ◽  
pp. 371-378 ◽  
Author(s):  
N.A. Mat Nor ◽  
L. Ismail ◽  
S.K.M. Jamari ◽  
K. Ramesh ◽  
B. Vengadaesvaran ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Copper Oxide ◽  
Double Layer ◽  
Water Uptake ◽  
Electrochemical Impedance ◽  
Double Layer Capacitance ◽  
Corrosion Performance ◽  
Content Type

Purpose This paper aims to analyse the coating behaviour in corrosion environment as well as to evaluate the best percentage amount of copper oxide and copper needed for organic coating in order to prevent the corrosion degradation. Electrochemical impedance spectroscopy (EIS) studies have been conducted in order to evaluate the corrosion performance of polyester-epoxy-copper oxide and polyester-epoxy-copper coating systems. Design/methodology/approach The availability of this modem instruments is used to obtain impedance data as well as computer programs to interpret the results that made the technique popular. In addition, EIS is well suited to the study of polymer-coated metals. Findings The results showed that samples containing 25 weight per cent of copper oxide and copper (90P25CuO and 90P25Cu) obtained the excellent corrosion properties from the first day up to 30 days of NaCl immersion. The highest corrosion resistance values obtained by 90P25CuO and 90P25Cu on the 30th day were 7.107 × 108 O and 5.701 × 108 O, respectively, with lower double layer capacitance of 1.407 × 10−9 Farad and 3.935 × 10−9 Farad, respectively. Moreover, the water uptake gained by these two coating samples was the lowest at the end of immersion, which was 0.0084 for 90P25CuO and 0.1592 for 90P25Cu, showing that the sample has good corrosion performance. Originality/value This paper discussed on the highest corrosion resistance, double layer capacitance and the water uptake of the copper (Cu) and copper oxide (CuO) coating system obtained from the EIS measurements.

Nanopore Size Estimation Using Electrochemical Impedance Spectroscopy Analysis

2008 ◽  
Author(s):  
Gou-Jen Wang ◽  
Ming-Chun Chien
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Pore Size ◽  
Double Layer ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Ion Concentration ◽  
Size Estimation ◽  
Transfer Resistance ◽  
Impedance Parameters

We present a simple and cost effective approach using electrochemical impedance spectroscopy (EIS) for accurate pore size estimation of silicon based nano-pores. This method accounts for the capacitor effects of the electrical double layer and the resistor effects of the ion concentration inside the nano-channel. The nano-pore impedance was modeled as the electrolyte charge transfer resistance Rs in a series connection with a parallel ion diffusion circuit Rf with a constant phase element (CPE) that models the behaviour of the double layer. The EIS analysis that has been widely employed to measure the energy storage and dissipation properties of a physicochemical system in frequency domain was adopted to sense the impedance parameters of the nano-pore. The nano-pore size was then estimated based on the impedance parameters. The accuracy of the estimated nano-pore size was verified by the TEM image.

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