MAGNETIC NANOPARTICLE BASED FLUORESCENCE IMMUNOASSAY FOR DETERMINATION OF OCHRATOXIN A

2020 ◽  
pp. 403-405
Author(s):  
Z. Becheva ◽  
M. Atanasova
Keyword(s):  
Magnetic Nanoparticles ◽  
Ochratoxin A ◽  
Polyclonal Antibody ◽  
Magnetic Nanoparticle ◽  
Fluorescein Isothiocyanate ◽  
Fluorescence Immunoassay ◽  
Constant Concentration ◽  
Competitive Immunoassay ◽  
Immunofluorescent Analysis

Ochratoxins are possible human carcinogens. The aim of this study is to develop a sensitive competitive immunofluorescent analysis for determination of ochratoxin A (OTA) on the base of immobilized polyclonal antibody against ochratoxin and F(ab)2 fragment on magnetic nanoparticles (MNPs). Competitive immunoassay was performed by using variety concentrations of OTA and constant concentration of fluorescein isothiocyanate (FITC) labeled OTA. The analytical characteristics of the analysis with immobilized polyclonal antibody and F(ab)2 fragment were very closely.

Magnetic Nanoparticle-Based Fluorescence Immunoassay for Determination of Ochratoxin A in Milk

2020 ◽  
Vol 13 (12) ◽  
pp. 2238-2248
Author(s):  
Zlatina Rumenova Becheva ◽  
Milka Koycheva Atanasova ◽  
Yavor Lukanov Ivanov ◽  
Tzonka Ivanova Godjevargova
Keyword(s):  
Ochratoxin A ◽  
Magnetic Nanoparticle ◽  
Fluorescence Immunoassay

Immunofluorescence Assay Using Monoclonal and Polyclonal Antibodies for Detection of Staphylococcal Enterotoxins A in Milk

2019 ◽  
Vol 13 (1) ◽  
pp. 137-145 ◽  
Author(s):  
Tzonka Godjevargova ◽  
Zlatina Becheva ◽  
Yavor Ivanov ◽  
Andrey Tchorbanov
Keyword(s):  
Monoclonal Antibody ◽  
Magnetic Nanoparticles ◽  
Polyclonal Antibody ◽  
Polyclonal Antibodies ◽  
Food Poisoning ◽  
Staphylococcal Enterotoxin ◽  
Staphylococcal Enterotoxin A ◽  
Fluorescence Immunoassay ◽  
Magnetic Separator ◽  
Milk Samples

Objectives: Staphylococcus aureus is a Gram-positive microorganism. S. aureus can grow in various foods and cause food poisoning by secreting enterotoxins. The most common enterotoxins involved in food poisoning are staphylococcal enterotoxin A and staphylococcal enterotoxin B, but Staphylococcal Enterotoxin A (SEA) is predominant. The main types of food contaminated with SEs are meat and meat products, poultry and eggs, milk and dairy products. The aim of this study was to develop a rapid and sensitive fluorescence immunoassay for detection of staphylococcal enterotoxin A in milk. Methods: Monoclonal and polyclonal antibodies for SEA were produced and characterized. Competitive fluorescence immunoassay based on Magnetic Nanoparticles (MNPs) was performed and optimized. MNPs were used as a solid carrier of the antibodies. The first step of the assay was immunoreaction between the immobilized antibody onto MNPs and SEA in milk sample. Then the fluorescein-SEA conjugate was added to the sample. Thus, competitive immunoreaction between MNP-mAb/MNP-pAb with SEA and SEA-FITC was performed. These immuno-complexes were separated by a magnetic separator and the obtained supernatants were analyzed. The fluorescent signal from the excess of conjugated SEA was proportional to the SEA contained in the milk. The assay duration was only 30 min. Results: The fluorescence immunoassays performed with polyclonal antibody had linear ranges from 5 pg/mL to 100 ng/mL SEA in a buffer, and from 50 pg/mL to 50 ng/mL SEA in spiked milk samples. While the same assays performed with monoclonal antibody had linear ranges from 1 pg/mL to 20 ng/mL SEA in buffer, and from 10 pg/mL to 10 ng/mL SEA in spiked milk samples. The detection limits of the developed immunoassays performed in milk were: 48 pg/mL with polyclonal antibody and 9 pg/mL with monoclonal antibody. Conclusion: A rapid and sensitive fluorescence immunoassay based on magnetic nanoparticles with a polyclonal and monoclonal antibody for determination of staphylococcal enterotoxin A in milk was developed.

scholarly journals Determination of Morphine in Human Urine by the Novel Competitive Fluorescence Immunoassay

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jie Cao ◽  
Xiao-Ying Chen ◽  
Wu-Rong Zhao
Keyword(s):  
Monoclonal Antibodies ◽  
Human Urine ◽  
Screening Tool ◽  
Fluorescein Isothiocyanate ◽  
Cross Reactivity ◽  
The Novel ◽  
Fluorescence Immunoassay ◽  
Coated Plate ◽  
Efficient Screening

A competitive fluorescence immunoassay for the identification and quantification of morphine has been developed on the basis of hapten-coated plate format. Hapten was prepared through covalent conjugating a morphine derivative with albumin bovine. In the immunoassay, the hapten was inoculated on a 96-well plate and then bound with monoclonal antibodies labeled with a signal indicating dye, fluorescein isothiocyanate (FITC). Unbound FITC-antibodies were rinsed off from the plate. The fluorescein intensity decreases in the presence of morphine molecules due to the competitively binding to antibodies against hapten. The intensity is inversely correlated with the concentration of morphine. In quantitative analysis for urine samples, we obtained a linearity range of 0.2 μg/mL∼2.5 μg/mL, along with a detection limit of c.a. 1 ng/mL. The fluorescence immunoassay shows low cross-reactivity (below 10%) to 6-acetylmorphine, 3-acetylmorphine, and heroine. The developed method produced comparable results to the standard GC-MS/MS method. In conclusion, a rapid and efficient screening tool for morphine in clinical human urine has been established.

Immunofluorescent Analysis with Magnetic Nanoparticles for Simultaneous Determination of Antibiotic Residues in Milk

2013 ◽  
Vol 46 (10) ◽  
pp. 1537-1552 ◽  
Author(s):  
Katya I. Gabrovska ◽  
Svetla I. Ivanova ◽  
Yavor L. Ivanov ◽  
Tzonka I. Godjevargova
Keyword(s):  
Magnetic Nanoparticles ◽  
Simultaneous Determination ◽  
Antibiotic Residues ◽  
Immunofluorescent Analysis

scholarly journals Field-dependent dynamic responses from dilute magnetic nanoparticle dispersions

Nanoscale ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 2052-2066 ◽  
Author(s):  
Jeppe Fock ◽  
Christoph Balceris ◽  
Rocio Costo ◽  
Lunjie Zeng ◽  
Frank Ludwig ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Ac Susceptibility ◽  
Bivariate Distribution ◽  
Dynamic Responses ◽  
Nanoparticle Dispersions ◽  
Field Dependent

AC susceptibility (ACS) and optomagnetic (OM) measurements vs. field and frequency allow determination of the bivariate distribution in moment and size. The obtained correlation provides information on the morphology of the magnetic nanoparticles.

scholarly journals Simultaneous Determination of Penicillin G and Chloramphenicol in Milk by a Magnetic Nanoparticle-Based Fluorescent Immunoassay

2020 ◽  
Vol 14 (1) ◽  
pp. 59-69
Author(s):  
Milka Atanasova ◽  
Yavor Ivanov ◽  
Elena Zvereva ◽  
Anatoly Zherdev ◽  
Tzonka Godjevargova
Keyword(s):  
Magnetic Nanoparticles ◽  
Simultaneous Determination ◽  
Magnetic Nanoparticle ◽  
Limit Of Detection ◽  
Animal Health ◽  
Simultaneous Detection ◽  
Penicillin G ◽  
Frequent Use ◽  
Simultaneous Immunoassay

Background: Antibiotic residues are a problem of increasing importance and have direct consequences for human and animal health. The frequent use of antibiotics in veterinary practice causes their excretion in milk in dairy cattle. This way, they can easily enter the human body through the consumption of milk and dairy products. Objectives: This induces the need for accurate and sensitive methods to monitor antibiotic levels in milk. The aim of this study was to develop a rapid and sensitive magnetic nanoparticle-based fluorescence immunoassay for the simultaneous detection of chloramphenicol and penicillin G in milk. Methods: Magnetic nanoparticles were synthesized and functionalized with (3-aminopropyl)triethoxysilane. Chloramphenicol-Ovalbumin and Chloramphenicol-Ovalbumin-Fluorescein-5-isothiocyanate conjugates were prepared. Penicillin G – ATTO 633 fluorescent conjugate was synthesized. Antibodies against chloramphenicol and penicillin G were immobilized onto the magnetic nanoparticles. The competitive fluorescent immunoassay was developed. The optimal concentration of the antibody-magnetic nanoparticles and the fluorescent conjugates for the assay was determined. The calibration curves for the antibiotics in buffer and milk were plotted. Fluorescent immunoassay for the simultaneous determination of chloramphenicol and penicillin G in milk was developed. Results: The limit of detection by the simultaneous immunoassay of chloramphenicol and penicillin G in milk was 0.85 ng/mL and 1.6 ng/mL, respectively. The recovery of different concentrations of chloramphenicol and penicillin G in milk samples varied from 98% to 106%. Conclusions: A rapid and sensitive magnetic nanoparticle-based immunofluorescent assay for the simultaneous determination of chloramphenicol and penicillin G in milk was developed. The magnetic nanoparticles ensured rapid and easy procedure.

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