scholarly journals Functionalized TiO2 Nanotube Platform for Gliadin Electroanalysis

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 22
Author(s):  
Cristina Dumitriu ◽  
Alexandra Constantinescu ◽  
Cristian Pirvu
Keyword(s):  
Complex System ◽  
Graphene Oxide ◽  
Electrochemical Impedance Spectroscopy ◽  
Detection Method ◽  
Electrochemical Impedance ◽  
Nanostructured Electrode ◽  
Lower Detection Limit ◽  
Linear Dependency ◽  
Lower Detection ◽  
Gliadin Antibody

The present paper presents a gliadin detection method. This method is based on a modified Ti electrode. Modification was performed by a simple and cheap anodization. Then, a layer of graphene oxide was added, and gliadin antibody was fixed on the electrode surface. Using this complex system, electrochemical impedance spectroscopy was used for gliadin detection. Solutions with known gliadin (a fraction from gluten) content were used for analysis. Impedance measured at a certain frequency and coating resistance were analyzed. Better results (good linearity and lower detection limit) were obtained by plotting impedance at a certain frequency versus gliadin concentration. Coating resistance was proved to be in linear dependency with gliadin concentration only at lower concentrations. This system based on titanium nanostructured electrode has the potential to be used for gluten contamination detection from foods.

GLUCOSE BIOSENSOR BASED ON DEXTRAN-Fe3O4 NANOCOMPOSITE MODIFIED SPCEs

2009 ◽  
Vol 21 (06) ◽  
pp. 437-440 ◽  
Author(s):  
Wen-Chang Chen ◽  
Yun-Ya Lin
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Glucose Biosensor ◽  
Precipitation Method ◽  
Carbon Electrodes ◽  
Electrochemical Characteristics ◽  
Lower Detection Limit ◽  
Lower Detection ◽  
Co Precipitation

Dextran-coating iron oxide (DCIO) nanoparticles were prepared by co-precipitation method and using dextran as the stabilizing agent. A glucose biosensor was successfully constructed firstly by simply drop-coating ferricyanide (Ferri)-DCIO onto screen-printed carbon electrodes (SPCEs), and then by layering-on glucose oxidase. The electrochemical characteristics of the modified SPCEs were analyzed by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. The optimal DCIO and enzyme loadings were 16 mg ml-1 and 0.7 U, respectively, and the sensitivity of the resulting biosensor was 0.4 μA mM-1 at 0.45 V with a wide linearity up to 44.4 mM glucose and the lower detection limit of about 1.23 mM.

scholarly journals Orthogonal Demodulation Pound–Drever–Hall Technique for Ultra-Low Detection Limit Pressure Sensing

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3223 ◽  
Author(s):  
Jinliang Hu ◽  
Sheng Liu ◽  
Xiang Wu ◽  
Liying Liu ◽  
Lei Xu
Keyword(s):  
Detection Limit ◽  
Detection Method ◽  
Wavelength Shift ◽  
Pressure Sensing ◽  
Frequency Sensitivity ◽  
Lower Detection Limit ◽  
Lower Detection ◽  
Shift Detection ◽  
Quality Factor Q ◽  
Hall Technique

We report on a novel optical microcavity sensing scheme by using the orthogonal demodulation Pound–Drever–Hall (PDH) technique. We found that larger sensitivity in a broad range of cavity quality factor (Q) could be obtained. Taking microbubble resonator (MBR) pressure sensing as an example, a lower detection limit than the conventional wavelength shift detection method was achieved. When the MBR cavity Q is about 105–106, the technique can decrease the detection limit by one or two orders of magnitude. The pressure-frequency sensitivity is 11.6 GHz/bar at wavelength of 850 nm, and its detection limit can approach 0.0515 mbar. This technique can also be applied to other kinds of microcavity sensors to improve sensing performance.

scholarly journals A Novel Method for the Detection of SARS-CoV-2 Based on Graphene-Impedimetric Immunosensor

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4230
Author(s):  
Gabriel C. Zaccariotto ◽  
Martin K. L. Silva ◽  
Giovanna S. Rocha ◽  
Ivana Cesarino
Keyword(s):  
Cyclic Voltammetry ◽  
Graphene Oxide ◽  
Electrochemical Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Rapid Diagnosis ◽  
Spike Protein ◽  
Electrochemical Immunoassay ◽  
Reduced Graphene ◽  
Novel Method ◽  
Impedimetric Immunosensor

Due to the SARS-CoV-2 pandemic, there has been an increase in the search for affordable healthcare devices for mass testing and rapid diagnosis. In this context, this work described a new methodology for SARS-CoV-2 detection based on an impedimetric immunosensor developed using the advantageous immobilization of antibodies in the reduced graphene oxide (rGO). The rGO was obtained by chemical synthesis from the commercial graphene oxide (GO), and the materials were morphologically, electrochemically and visually characterized. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques were used to evaluate the fabrication steps of the immunosensor. The electrochemical immunoassay was considered for SARS-CoV-2 spike protein RBD detection using a impedimetric immunosensor and redox couple ([(Fe(CN)6)]3−/4−) as a probe. The immunosensor was effectively developed and applied in the detection of SARS-CoV-2 spike protein RBD in saliva samples.

Differentiation between graphene oxide and reduced graphene by electrochemical impedance spectroscopy (EIS)

2012 ◽  
Vol 20 ◽  
pp. 63-66 ◽  
Author(s):  
E. Casero ◽  
A.M. Parra-Alfambra ◽  
M.D. Petit-Domínguez ◽  
F. Pariente ◽  
E. Lorenzo ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Reduced Graphene

Immunodiagnosis of paramphistomosis using monoclonal antibody-based sandwich ELISA for detection ofParamphistomum gracilecirculating 16 kDa antigen

Parasitology ◽  
2017 ◽  
Vol 144 (7) ◽  
pp. 899-903 ◽  
Author(s):  
PANAT ANURACPREEDA ◽  
KULLANID TEPSUPORNKUL ◽  
RUNGLAWAN CHAWENGKIRTTIKUL
Keyword(s):  
Monoclonal Antibody ◽  
Detection Method ◽  
Sandwich Elisa ◽  
Enzyme Linked Immunosorbent Assay ◽  
Microtitre Plate ◽  
Serum Samples ◽  
Fecal Samples ◽  
Lower Detection Limit ◽  
Lower Detection ◽  
Sensitivity Specificity

SUMMARYIn this study, we have produced a monoclonal antibody (MoAb) against 16 kDa antigen ofParamphistomum gracile(16 kDaAgPg), and developed an accurate sandwich enzyme-linked immunosorbent assay (sandwich ELISA) for the detection of circulating 16 kDaAg in the serum and fecal samples from cattle naturally infected withP. gracile. MoAb 1D10 was immobilized on a microtitre plate, and the antigen in the samples was captured and detected with biotinylated rabbit anti-16 kDaAgPg antibody. The lower detection limit of sandwich ELISA was 3·5 pg mL−1, and no cross-reaction with other parasite antigens was evaluated. The reliability of the assay was examined using the serum and fecal samples from cattle naturally infected withP. gracile, Fasciola gigantica, Moniezia benedeni, Trichurissp.,Strongyloidessp., strongylids and non-infected animals. The sandwich ELISA showed the sensitivity, specificity and accuracy at 98·33, 100 and 99·55% (serum samples), and 96·67, 100 and 99·09% (fecal samples). Therefore, this detection method is a rapid and excellent potential assay for the accurate diagnosis of paramphistomosis.

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