A Highly Sensitive Fluorescence Immunoassay for the Determination of Diethylstilbestrol

2013 ◽  
Vol 295-298 ◽  
pp. 622-625
Author(s):  
Xin Yi Wang ◽  
Wen Dong ◽  
Wei Li Xue ◽  
Shu Hao Wang
Keyword(s):  
Detection Limit ◽  
Optimal Conditions ◽  
Fluorescence Immunoassay ◽  
Rabbit Igg ◽  
Highly Sensitive ◽  
Amplification System ◽  
Analytical Range ◽  
Antibody Coating

A highly sensitive direct competitive fluorescence immunoassay (FIA) was developed for the determination of diethylstilbestrol (DES), based on the antibody coating format using biotin-streptavidin amplification system. In the assay, DES competed with biotinylated goat anti-rabbit IgG for the immobilized antibody, then the streptavidin-FITC was added to link to the biotinylated goat anti-rabbit IgG as a tracer. Under optimal conditions, the assay provided a wide analytical range of 0.001-10000 ng/mL with a detection limit of 2.91×10-4ng/mL (R2=0.9943). This method was then applied to the determination of DES in chicken with satisfactory results

Radioimmunoassay for pregnancy-associated plasma protein A.

1982 ◽  
Vol 28 (1) ◽  
pp. 50-53 ◽  
Author(s):  
M J Sinosich ◽  
B Teisner ◽  
J Folkersen ◽  
D M Saunders ◽  
J G Grudzinskas
Keyword(s):  
Detection Limit ◽  
Amniotic Fluid ◽  
Plasma Protein ◽  
Early Pregnancy ◽  
Twin Pregnancy ◽  
Protein A ◽  
Trophoblastic Disease ◽  
Coefficients Of Variation ◽  
Highly Sensitive

Abstract A specific and highly sensitive radioimmunoassay for determination of pregnancy-associated plasma protein A in human serum is described. The minimum detection limit for this protein was 2.9 micrograms/L. The within- and between-assay coefficients of variation were 4.0 and 4.5%, respectively. The circulating protein was detected within 32 days of conception in eight normal pregnancies and within 21 days in a twin pregnancy. Circulating concentrations in the mother at term were consistently higher (10-fold) than in matched amniotic fluid; none was detected in the umbilical circulation. This protein was also detected in the circulation of patients with hydatiform mole. This assay will permit investigations into the clinical evaluation of measurements of the protein during early pregnancy and trophoblastic disease.

Highly Sensitive Determination of Dopamine Using Osmium/Nafion Modified Disposable Integrated Biosensor

2009 ◽  
Vol 60-61 ◽  
pp. 311-314 ◽  
Author(s):  
Chun Xiu Liu ◽  
Hong Min Liu ◽  
Qing De Yang ◽  
Nan Sen Lin ◽  
Yi Lin Song ◽  
...  
Keyword(s):  
Detection Limit ◽  
Correlation Coefficient ◽  
Gold Electrode ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Redox Polymer ◽  
Highly Sensitive ◽  
Sensitive Determination ◽  
Excellent Reproducibility

A biosensor based on gold electrode modified by Pt nanaoparticles/Osmium redox polymer/Nafion trilayer film was fabricated and used for selective and sensitive determination of dopamine. The biosensor is explored for DA sensing using the cyclic voltammetry (CV), amperometric and differential pulse voltammetric (DPV) methods. The CV anodic peak currents showed a linear range with a correlation coefficient of 0.996, localized in the concentration range 0~192 μM. The differential pulse voltammetric (DPV) peak currents were linear with DA concentration during 2~425 μM with correlation coefficient of 0.99. The biosensor showed high sensitivity of 0.5 nA /nM cm2 and excellent reproducibility with the detection limit of ~10 nM (S/N=3) for the determination of DA. The easy fabrication, low detection limit and high sensitivity of the integrated biosensor making it particularly suitable for the analytical purposes.

scholarly journals Determination of epinephrine by the Briggs-Rauscher oscillating system using non-equilibrium stationary state

2012 ◽  
Vol 77 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Jinzhang Gao ◽  
Yanjun Liu ◽  
Jie Ren ◽  
Xiaoli Zhang ◽  
Li Ming ◽  
...  
Keyword(s):  
Detection Limit ◽  
Stationary State ◽  
Lower Detection Limit ◽  
Highly Sensitive ◽  
Lower Detection ◽  
Oscillating Reaction ◽  
The Difference ◽  
Foreign Species ◽  
Non Equilibrium

A highly sensitive method for the determination of epinephrine was proposed, which was based on the perturbation of epinephrine to Briggs-Rauscher oscillating system involving malonic acid, Mn2+, H+, IO3 - and H2O2 at non-equilibrium stationary state. The concentration of KIO3 was chosen as a control parameter to find the bifurcation point in this paper. Results showed that a well linear relationship between the difference of potential and the negative logarithm concentrations of epinephrine existed in the range of 1.1?10-7?5.2?10-9 mol L-1 with a lower detection limit of 6.8?10-10mol L-1 and a correlation coefficient of 0.9974. Compared to the classical oscillating reaction, this method has a lower detection limit and wider linear range. The effects of some foreign species, which may possibly be existed with epinephrine, on determination were also investigated. The proposed method has been successfully used to determine the epinephrine both in the serum and adrenaline hydrochloride injection.

Development of a Highly Sensitive Chemiluminescence Enzyme Immunoassay for the Determination of Bisphenol A

2013 ◽  
Vol 726-731 ◽  
pp. 1283-1286
Author(s):  
Li Rui Liu ◽  
Li Qin Liu ◽  
Xue Qing Chen ◽  
Guo Qing Shi
Keyword(s):  
Detection Limit ◽  
Bisphenol A ◽  
Enzyme Immunoassay ◽  
Rapid Determination ◽  
Secondary Antibody ◽  
Average Recovery ◽  
Highly Sensitive ◽  
Optimized Conditions ◽  
Chemiluminescence Enzyme Immunoassay

A highly sensitive chemiluminescence enzyme immunoassay (CLEIA) method for the determination of bisphenol A (BPA) was developed, which used a secondary antibody labeled with horseradish peroxidase detected with a luminol-based substrate. Under the optimized conditions, the linear range was 0.01μg/mL~0.74μg/mL, and the detection limit was 0.008μg/mL. The average recovery for BPA in barreled water was 104%. This developed method could be applied for the selective, high-throughput, and rapid determination of BPA in barreled water.

Fluorimetric Method for the Determination of Trace Amounts of Molybdenum Using 2-Hydroxy-1-Naphthaldehydene-p-Aminotoluene

2014 ◽  
Vol 556-562 ◽  
pp. 584-587 ◽  
Author(s):  
Wei Wei Bian
Keyword(s):  
Detection Limit ◽  
Cation Exchange ◽  
Good Precision ◽  
Pig Liver ◽  
Fluorimetric Method ◽  
Ethanol Medium ◽  
Spectrofluorimetric Method ◽  
Highly Sensitive ◽  
Precision And Accuracy

A new fluorescent reagent, 2-hydroxy-1-naphthaldehydene-p-aminotoluene, was synthesized. The fluorescent reaction of this reagent with molybdenum was studied. Based on this chelation, a highly sensitive spectrofluorimetric method was developed for determination of trace amounts of molybdenum in a water-ethanol medium at pH 6.8. Under these conditions, the Mo-HNA complex has excitation and emission maxima at 300 and 380 nm, respectively. The linear range of the method is 0-2μg/L and the detection limit is 0.62μg/L. Interference of other ions was studied. It is necessary to remove the interfering cations through cation exchange. The procedure can be carried out easily and affords good precision and accuracy. This method has been successfully applied to the determination of molybdenum in pig liver and mussels.

scholarly journals Enhancement of stripping technique for Copper(II) detection in water sample using N,N’-bis(2-hydroxy-4-methoxyacetophenone)ethylenediamine (BME)

2014 ◽  
Vol 10 (3) ◽  
Author(s):  
Syaza Azhari ◽  
Rahmalan Ahamad ◽  
Farediah Ahmad
Keyword(s):  
Tap Water ◽  
Optimal Conditions ◽  
Adsorbed Species ◽  
Accumulation Time ◽  
Highly Sensitive ◽  
Experimental Parameters ◽  
Scan Rate ◽  
Interfering Ions ◽  
Determination Of Copper

A highly sensitive, rapid, simple and selective stripping assay for the determination of trace copper(II) is proposed.  The selectivity and sensitivity of the electroanalytical process on a glassy carbon (GC) electrode were enhanced using the newly synthesized Schiff base N,N’-bis(2-hydroxy-4-methoxyacetophenone)ethylenediamine (BME). The methodology is based on the accumulation of copper(II)–BME complex onto the GC electrode, followed by electrochemical oxidation of the adsorbed species. The effect of experimental parameters such as pH, BME concentration, scan rate, accumulation time and accumulation potential on the sensitivity of copper(II) detection were investigated. Under the optimal conditions, BME has successfully enhanced the copper(II) detection using the GC electrode by nearly 95% with detection limit (LOD) of  2.6 ngL−1. The effects of interfering ions such as Cd(II), Zn(II), Fe(II), Cr(III) and Pb(II) were also investigated. The applicability of this technique was illustrated by the determination of copper(II) ion in tap water.________________________________________GRAPHICAL ABSTRACT 

Ultrasensitive Thyrotropin Immunoassay Based on Enzymatically Amplified Time-Resolved Fluorescence with a Terbium Chelate

1992 ◽  
Vol 38 (4) ◽  
pp. 545-548 ◽  
Author(s):  
A Papanastasiou-Diamandi ◽  
T K Christopoulos ◽  
E P Diamandis
Keyword(s):  
Alkaline Phosphatase ◽  
Detection Limit ◽  
Solid Phase ◽  
Thyroid Stimulating Hormone ◽  
Fluorescence Immunoassay ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Highly Sensitive ◽  
Assay Time ◽  
Highly Sensitive Detection

Abstract We describe an ultrasensitive, enzymatically amplified time-resolved fluorescence immunoassay of thyrotropin (thyroid-stimulating hormone) in serum with use of a terbium chelate as the detectable moiety. In this assay, thyrotropin is first simultaneously reacted with a solid-phase (microtiter well) monoclonal antibody and a soluble biotinylated monoclonal detection antibody. After washing, a streptavidin-alkaline phosphatase conjugate is added, followed by another washing. Alkaline phosphatase acts on the substrate 5-fluorosalicyl phosphate (FSAP) to produce 5-fluorosalicylic acid (FSA). FSA, but not FSAP, can then form with Tb3+ and EDTA a highly fluorescent ternary complex of long fluorescence lifetime. This complex is quantified with time-resolved fluorometry. The thyrotropin assay is highly sensitive (detection limit approximately 0.003 milli-int. unit/L when a total assay time of 85 min is used), precise, and accurate. The thyrotropin assay can also be completed in less than 30 min (detection limit 0.013 milli-int. unit/L), thus making this procedure a candidate technology for high-throughput automated analyzers.

Determination of Chloramphenicol Residues in Aquatic Products Using Immunoaffinity Column Cleanup and High Performance Liquid Chromatography with Ultraviolet Detection

2013 ◽  
Vol 96 (4) ◽  
pp. 897-901 ◽  
Author(s):  
Qing-Jie Zhang ◽  
Tao Peng ◽  
Dong-Dong Chen ◽  
Jie Xie ◽  
Xiong Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Ammonium Hydroxide ◽  
Optimal Conditions ◽  
Immunoaffinity Column ◽  
Ultraviolet Detection ◽  
Aquatic Products ◽  
Highly Sensitive ◽  
The Mean

Abstract A method based on HPLC with UV detection was developed for the quantitative determination of chloramphenicol (CAP) residues in aquatic products. The samples were extracted with ethyl acetate–ammonium hydroxide (98 + 2, v/v), followed by a cleanup step using an immunoaffinity column. The analytes were determined by HPLC-UV. Optimal conditions for the extraction and cleanup procedures are described. The linear regression equation was y = 91.47x – 8.60 with R2 = 0.9998 (y = peak area and x = CAP concentration) and showed a good reproducibility. The LOQ was 0.25 μg/kg for determining CAP spiked in the aquatic products. The mean recoveries of CAP from fish and shrimp samples fortified at 0.25–1.0 μg/kg were 88.7–93.1 and 92.0–97.3%, respectively; the repeatability RSDs were less than 8.1%. It was concluded that the method is simple, highly sensitive, and low cost for quantitatively measuring CAP residues in aquatic products. Analyte identification was confirmed by HPLC/MS/MS analysis.

scholarly journals Solid Phase Extraction of Trace Amounts of Praseodymium Using Transcarpathian Clinoptilolite

2019 ◽  
Vol 3 (1) ◽  
pp. 27 ◽  
Author(s):  
Olha Stashkiv ◽  
Volodymyr Vasylechko ◽  
Galyna Gryshchouk ◽  
Ihor Patsay
Keyword(s):  
Detection Limit ◽  
Solid Phase Extraction ◽  
Sorption Capacity ◽  
Flow Rate ◽  
Salt Solution ◽  
Ph Value ◽  
Solid Phase ◽  
Phase Extraction ◽  
Optimal Conditions

Sorptive properties of the Transcarpathian clinoptilolite towards Pr(III) were studied under dynamic conditions. The sorption capacity of clinoptilolite under optimal conditions (sorbent grain diameter of 0.20–0.31 mm; pH 9.0, temperature of preliminary precalcination of 350 °C, and flow rate of the Pr(III) salt solution with the concentration of 1.0 μg·mL−1 through the sorbent of 5 mL·min−1) was equal to 47.5 mg·g−1. The best desorbent of Pr from the clinoptilolite was the 1 M solution of KCl acidified with HCl to a pH value of 3.0. The method of Pr(III) trace amounts preconcentration in a solid phase extraction mode with further determination of this REE via spectrophotometric technique was developed. The linearity of the proposed method was evaluated in the range of 2–100 ng·mL−1 with detection limit of 0.7 ng·mL−1.

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