scholarly journals Monoclonal Antibody-Based Immunosensor for the Electrochemical Detection of Chlortoluron Herbicide in Groundwaters

Biosensors ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 513
Author(s):  
Anaïs Surribas ◽  
Lise Barthelmebs ◽  
Thierry Noguer
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Detection Limit ◽  
Electrochemical Detection ◽  
Matrix Effects ◽  
Competitive Binding ◽  
Carbon Electrodes ◽  
Dimethyl Urea ◽  
Grass Weed

Chlortoluron (3-(3-chloro-p-tolyl)-1,1-dimethyl urea) is an herbicide widely used in substitution to isoproturon to control grass weed in wheat and barley crops. Chlortoluron has been detected in groundwaters for more than 20 years; and dramatic increases in concentrations are observed after intense rain outbreaks. In this context; we developed an immunosensor for the determination of chlortoluron based on competitive binding of specific monoclonal antibodies on chlortoluron and immobilized biotinylated chlortoluron; followed by electrochemical detection on screen-printed carbon electrodes. The optimized immunosensor exhibited a logarithmic response in the range 0.01–10 µg·L−1; with a calculated detection limit (LOD) of 22.4 ng·L−1; which is below the maximum levels allowed by the legislation (0.1 µg·L−1). The immunosensor was used for the determination of chlortoluron in natural groundwaters, showing the absence of matrix effects.

scholarly journals Direct Assay for Cobalamin Bound to Transcobalamin (Holo-Transcobalamin) in Serum

2002 ◽  
Vol 48 (3) ◽  
pp. 526-532 ◽  
Author(s):  
Marius Ulleland ◽  
Ingar Eilertsen ◽  
Edward V Quadros ◽  
Sheldon P Rothenberg ◽  
Sergey N Fedosov ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Detection Limit ◽  
Quantitative Determination ◽  
Reliable Method ◽  
Solid Phase ◽  
Reference Interval ◽  
Magnetic Microspheres ◽  
Affinity Constant ◽  
Capture Assay

Abstract Background: Only cobalamin carried by transcobalamin (holo-transcobalamin) is available for cellular uptake and hence is physiologically relevant. However, no reliable or accurate methods for quantifying holo-transcobalamin are available. We report a novel holo-transcobalamin assay based on solid-phase capture of transcobalamin. Methods: A monoclonal antibody specific for human transcobalamin with an affinity constant >1010 L/mol was immobilized on magnetic microspheres to capture and concentrate transcobalamin. The cobalamin bound to transcobalamin was then released and assayed by a competitive binding radioassay. The quantification of holo-transcobalamin was accomplished using calibrators composed of recombinant, human holo-transcobalamin. Results: The assay was specific for holo-transcobalamin and had a detection limit of 5 pmol/L. Within-run and total imprecision (CV) was 5% and 8–9%, respectively. The working range (CV <20%) was 5–370 pmol/L. Dilutions of serum were linear in the assay range. The recovery of recombinant, human holo-transcobalamin added to serum was 93–108%. A 95% reference interval of 24–157 pmol/L was established for holo-transcobalamin in 105 healthy volunteers 20–80 years of age. For 72 of these sera, holo-haptocorrin and total cobalamin were also determined. Whereas holo-haptocorrin correlated well (r2 = 0.87) with total cobalamin, holo-transcobalamin correlated poorly (r2 = 0.23) with total cobalamin or holo-haptocorrin. Conclusions: The solid-phase capture assay provides a simple, reliable method for quantitative determination of holo-transcobalamin in serum.

Electrocatalysis and Sensitive Determination of Sudan I at Fe3O4/Graphene Modified Glassy Carbon Electrodes

2013 ◽  
Vol 401-403 ◽  
pp. 775-778
Author(s):  
Su Xing Luo ◽  
Yuan Hui Wu ◽  
Hua Gou
Keyword(s):  
Iron Oxide ◽  
Detection Limit ◽  
Electrochemical Method ◽  
Food Samples ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes ◽  
Sudan I ◽  
Anodic Peak Current ◽  
Sensitive Determination

The iron oxide/graphene (Fe3O4/rGO) nanocomposite modified electrode and the electrochemical properties of Sudan I were investigated. It was found the anodic peak current of Sudan I was linear with the concentration of Sudan I from 0.008 μM to 6 μM with a detection limit of 0.0005 μM (S/N=3). The regression equation was: Ipa (μA)=-0.8151-0.9651c (μM), R=0.9934. It was convenient and excellent sensitive electrochemical method for Sudan I determination. This electrochemical method was successfully applied to determine Sudan I in food samples.

Competitive heterogeneous enzyme immunoassay for theophylline by flow-injection analysis with electrochemical detection of p-aminophenol

1990 ◽  
Vol 36 (4) ◽  
pp. 662-665 ◽  
Author(s):  
E P Gil ◽  
H T Tang ◽  
H B Halsall ◽  
W R Heineman ◽  
A S Misiego
Keyword(s):  
Alkaline Phosphatase ◽  
Detection Limit ◽  
Electrochemical Detection ◽  
Flow Injection ◽  
Flow Injection Analysis ◽  
General Procedure ◽  
Amperometric Detection ◽  
Enzyme Label ◽  
Commercial Kit

Abstract A competitive enzyme-linked immunoabsorbent assay based on the flow-injection amperometric detection of p-aminophenol has been investigated with use of the materials and general procedure of a commercial kit for the determination of theophylline in human serum. The antibody is immobilized on glass beads, and the enzyme label is alkaline phosphatase (EC 3.1.3.1). The high currents generated during the electrochemical detection allowed a rapid (35 min) and simple determination of theophylline throughout its therapeutic range (10-20 mg/L) and also in the subtherapeutic range (detection limit of about 80 micrograms/L).

Two-monoclonal-antibody "sandwich"-type assay of human lutropin, with no cross reaction with choriogonadotropin.

1987 ◽  
Vol 33 (9) ◽  
pp. 1603-1607 ◽  
Author(s):  
W D Odell ◽  
J Griffin
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Detection Limit ◽  
Dose Response ◽  
Response Curve ◽  
Cross Reaction ◽  
Dose Response Curve ◽  
Low Doses ◽  
Human Choriogonadotropin ◽  
Sandwich Type

Abstract We have developed a sensitive, specific, noncompetitive sandwich-type assay for human lutropin (hLH). Two monoclonal antibodies are used, and there is no cross reaction with human choriogonadotropin (hCG) or human follitropin (hFSH), and little or none with human thyrotropin (hTSH). There also is no reaction with the free beta chains of hLH and hCG. The detection limit is less than 0.5 int. units of hLH per liter of serum, and the dose-response curve is linear between 0 and 10 int. units/L. The intra-assay CV averaged 5.4% at low doses of hLH; the interassay CV averaged 12.5%.

Direct electrochemical detection of trichothecenes in wheat samples using a 96-well electrochemical plate coupled with microwave hydrolysis

2009 ◽  
Vol 2 (2) ◽  
pp. 239-245 ◽  
Author(s):  
F. Ricci ◽  
F. Pino ◽  
M. Abagnale ◽  
M. Messia ◽  
E. Marconi ◽  
...  
Keyword(s):  
Detection Limit ◽  
Electrochemical Detection ◽  
Sensitive Detection ◽  
Feed Consumption ◽  
Aqueous Acetonitrile ◽  
Screen Printed Electrodes ◽  
Microwave Hydrolysis ◽  
Screen Printed

The use of a 96-well electrochemical plate for the fast and sensitive detection of deoxynivalenol and nivalenol in wheat samples is shown. Deoxynivalenol and nivalenol are hydrolysed using a microwave hydrolysis procedure (2 min) which leads to the production of electroactive compounds that can be sensitively detected by the use of cheap screen-printed electrodes. A procedure of extraction with aqueous acetonitrile and a clean-up step was demonstrated to be suitable for the application with wheat samples providing suitable detection limit (LOD=1.1 µg/g) and working range (2-20 µg/g) for the determination of deoxynivalenol in cereals for feed consumption.

scholarly journals Determination of Haptoglobin in Bovine Serum using Polyclonal and Monoclonal Anti-human Haptoglobin Antibodies

2010 ◽  
Vol 79 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Paulina Jawor ◽  
Tadeusz Stefaniak ◽  
Iwona Kątnik-Prastowska
Keyword(s):  
Monoclonal Antibody ◽  
Detection Limit ◽  
Bovine Serum ◽  
Solid Phase ◽  
Low Cost ◽  
Reference Method ◽  
Serum Samples ◽  
Incubation Periods ◽  
Short Time

Two ELISA procedures to determine haptoglobin (Hp) in bovine serum were developed. Equine haemoglobin was used as the solid phase. Self-developed goat polyclonal antibody (variant I) and monoclonal antibody (variant II) raised against human Hp were used. The results were compared with the guaiacol method. High correlation was found (r = 0.96 and r = 0.90, respectively) based on the results of 548 bovine serum samples, of which 357 were from clinically healthy cows and 191 from cows and calves monitored during treatment for the most common diseases. The Hp detection limit of ELISA using polyclonal Ab was 0.1 mg/l and using MoAb 0.21 mg/l. The addition of 2% PEG 6000 at the antibody-binding steps enabled major shortening of the incubation periods. The relatively short time, low cost of reagents, and high correlation with the reference method support the use of these ELISA variants in bovine diagnostics.

scholarly journals The determination of N-methylcarbamate pesticides using enzyme immunoassays with chemiluminescent detection

2004 ◽  
Vol 22 (SI - Chem. Reactions in Foods V) ◽  
pp. S280-S282 ◽  
Author(s):  
B. Mičková ◽  
P. Rauch ◽  
A. Montoya ◽  
E. Ferri ◽  
F. Fini ◽  
...  
Keyword(s):  
Detection Limit ◽  
Matrix Effects ◽  
Colorimetric Detection ◽  
Fruit Juices ◽  
Analytical Performance ◽  
Experimental Comparison ◽  
Enzyme Immunoassays ◽  
Chemiluminescent Detection ◽  
Concentration Levels

In the present work, enzyme-linked immunosorbent assays (ELISAs) with chemiluminescent detection for the determination of carbofuran, carbaryl and methiocarb were developed and the analytical parameters of these assays were compared with those of ELISAs with colorimetric detection. The sensitivity of immunochemical methods was expressed as detection limit, linear working range, and I<sub>50</sub> value. In comparison with colorimetric ELISA, the ability of the chemiluminescent reagents to detect lower concentrations of HRP allowed to decrease the optimal antibody and conjugate concentrations and to reach better analytical parameters. The experimental comparison of the analytical performance of the ELISAs was carried out by analysing simply diluted fruit juices, spiked at different concentration levels with the above mentioned pesticides. Recovery values for both ELISAs were around 100% and no matrix effects were observed when fruit juices were diluted 1:20 or more.

X-Ray Fluorescence Determination of Barium and Strontium in Geologic Samples

1971 ◽  
Vol 25 (3) ◽  
pp. 316-318 ◽  
Author(s):  
Brent P. Fabbi
Keyword(s):  
Detection Limit ◽  
Matrix Effects ◽  
Analytical Line ◽  
X Ray ◽  
First Order ◽  
Fluorescence Determination ◽  
Geologic Samples ◽  
Line Iron

It is possible to accurately determine barium and strontium in a variety of geologic samples by the XRF method proposed herein after correcting for matrix effects. The first-order (I) titanium Kα1 line interferes spectrally with the barium first-order (I) Lα1 analytical line. Iron significantly absorbs the emitted strontium x-ray quanta. Both of these effects were investigated in detail and a method of correcting for them developed. Detection limit for both elements is about 10 ppm.

Direct measurement of creatine kinase-MB activity in serum after extraction with a monoclonal antibody specific to the MB isoenzyme.

1986 ◽  
Vol 32 (4) ◽  
pp. 657-663 ◽  
Author(s):  
H C Vaidya ◽  
Y Maynard ◽  
D N Dietzler ◽  
J H Ladenson
Keyword(s):  
Monoclonal Antibody ◽  
Creatine Kinase ◽  
Monoclonal Antibodies ◽  
Room Temperature ◽  
Direct Determination ◽  
Myeloma Cell ◽  
Myeloma Cell Line ◽  
Latex Beads ◽  
Creatine Kinase Mb

Abstract Fusion of splenocytes from A/J mice immunized by creatine kinase (EC 2.7.3.2)-MB isoenzyme (CK-MB) with SP2/0-Ag14 myeloma cell line generated hybridomas producing monoclonal antibodies specific to CK-MB. One of these monoclonal antibodies ("Conan-MB") was used to develop a direct assay for CK-MB activity. In the assay, serum is incubated for 30 min at room temperature with "Conan-MB" immobilized on latex beads. The beads are then washed, and CK-MB activity bound to the antibody is measured after incubation with CK enzyme reagent for 30 min at 37 degrees C. Results with the assay correlated well (r = 0.997) with those for CK-MB concentration as measured by a two-site immunoassay. Neither CK-MM, CK-BB, mitochondrial CK, nor a hemolysate of erythrocytes interfered. Use of this unique monoclonal antibody allows rapid, precise, and direct determination of CK-MB activity.

scholarly journals Quantitative Determination of Acetamiprid in Pollen Based on a Sensitive Enzyme-Linked Immunosorbent Assay

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1265 ◽  
Author(s):  
Qingkui Fang ◽  
Quan Zu ◽  
Xiude Hua ◽  
Pei Lv ◽  
Wanwen Lin ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Detection Limit ◽  
Quantitative Determination ◽  
Immunosorbent Assay ◽  
Linear Range ◽  
Enzyme Linked Immunosorbent Assay ◽  
Experimental Conditions ◽  
Coating Antigen ◽  
Relative Standard

A sensitive biotinylated indirect competitive enzyme-linked immunosorbent assay (Bic-ELISA) was developed to detect acetamiprid pesticides in pollen, based on the heterogeneous coating antigen and biotinylated anti-acetamiprid monoclonal antibody. Under optimized experimental conditions, the detection limit for the Bic-ELISA was 0.17 ng/mL and the linear range was 0.25–25 ng/mL. The cross-reactivities could be regarded as negligible for the biotinylated antibodies with their analogues except for thiacloprid (1.66%). Analyte recoveries for extracts of spiked pollen (camellia pollen, lotus pollen, rape pollen) ranged from 81.1% to 108.0%, with intra-day relative standard deviations (RSDs) of 4.8% to 10.9%, and the average reproducibility was 85.4% to 110.9% with inter-assay and inter-assay RSDs of 6.1% to 11.7%. The results of Bic-ELISA methods for the Taobao’s website samples were largely consistent with HPLC-MS/MS. Therefore, the established Bic-ELISA methods would be conducive to the monitoring of acetamiprid in pollen.

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