scholarly journals Magnetic Lateral Flow Immunoassays

Diagnostics ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 288 ◽  
Author(s):  
Amanda Moyano ◽  
Esther Serrano-Pertierra ◽  
María Salvador ◽  
José Carlos Martínez-García ◽  
Montserrat Rivas ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Limit Of Detection ◽  
Current Knowledge ◽  
Immunomagnetic Separation ◽  
Sensitivity Enhancement ◽  
Lateral Flow ◽  
Rapid Separation ◽  
Latex Beads ◽  
New Generation

A new generation of magnetic lateral flow immunoassays is emerging as powerful tool for diagnostics. They rely on the use of magnetic nanoparticles (MNP) as detecting label, replacing conventional gold or latex beads. MNPs can be sensed and quantified by means of external devices, allowing the development of immunochromatographic tests with a quantitative capability. Moreover, they have an added advantage because they can be used for immunomagnetic separation (IMS), with improvements in selectivity and sensitivity. In this paper, we have reviewed the current knowledge on magnetic-lateral flow immunoassay (LFIA), coupled with both research and commercially available instruments. The work in the literature has been classified in two categories: optical and magnetic sensing. We have analysed the type of magnetic nanoparticles used in each case, their size, coating, crystal structure and the functional groups for their conjugation with biomolecules. We have also taken into account the analytical characteristics and the type of transduction. Magnetic LFIA have been used for the determination of biomarkers, pathogens, toxins, allergens and drugs. Nanocomposites have been developed as alternative to MNP with the purpose of sensitivity enhancement. Moreover, IMS in combination with other detection principles could also improve sensitivity and limit of detection. The critical analysis in this review could have an impact for the future development of magnetic LFIA in fields requiring both rapid separation and quantification.

scholarly journals Development of Lateral Flow Immunochromatographic Assays Using Colloidal Au Sphere and Nanorods as Signal Marker for the Determination of Zearalenone in Cereals

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 281 ◽  
Author(s):  
Mingfei Pan ◽  
Tianyu Ma ◽  
Jingying Yang ◽  
Shijie Li ◽  
Shengmiao Liu ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Fumonisin B1 ◽  
Test Strip ◽  
Food Samples ◽  
Cross Reactivity ◽  
Lateral Flow ◽  
Rapid Screening ◽  
Colloidal Au ◽  
Short Time

This paper describes the development of lateral flow immunochromatographic assays (ICAs) using colloidal Au sphere (SP) and nanorods (NRs) as signal markers for the determination of zearalenone (ZEN) in cereals. The developed ICAs can detect the analyte ZEN within a short time (10 min), and achieve lower limit of detection (LOD). This is the first time that the AuNRs are used as signal probe in immune test strip for ZEN detection. For colloidal AuSP immunochromatographic analysis (AuSP-ICA), the LODs in solution and spiked cereal sample were 5.0 μg L−1 and 60 μg kg−1, and for AuNRs immunochromatographic analysis (AuNRs-ICA) the two LODs achieved 3.0 μg L−1 and 40 μg kg−1, respectively. These two proposed ICAs have minor cross-reaction to the structural analogs of ZEN, and no cross-reactivity with aflatoxin B1, T-2 toxin, ochratoxin A, deoxynivalenol, fumonisin B1. Both of the developed ICAs can specifically and sensitively detect ZEN in cereals, providing an effective strategy for rapid screening and detection of ZEN in a large number of food samples.

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.

scholarly journals Determination of Residual Nonsteroidal Anti-Inflammatory Drugs in Aqueous Sample Using Magnetic Nanoparticles Modified with Cetyltrimethylammonium Bromide by High Performance Liquid Chromatography

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Malihe Khoeini Sharifabadi ◽  
Mohammad Saber-Tehrani ◽  
Syed Waqif Husain ◽  
Ali Mehdinia ◽  
Parviz Aberoomand-Azar
Keyword(s):  
Magnetic Nanoparticles ◽  
Cetyltrimethylammonium Bromide ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Aqueous Sample ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Inflammatory Drugs ◽  
Anti Inflammatory

A simple and sensitive solid-phase extraction method for separation and preconcentration of trace amount of four nonsteroidal anti-inflammatory drugs (naproxen, indomethacin, diclofenac, and ibuprofen) using Fe3O4magnetic nanoparticles modified with cetyltrimethylammonium bromide has been developed. For this purpose, the surface ofMNPswas modified with cetyltrimethylammonium bromide (CTAB) as a cationic surfactant. Effects of different parameters influencing the extraction efficiency of drugs including the pH, amount of salt, shaking time, eluent type, the volume of solvent, amount of adsorbent, sample volume, and the time of desorption were investigated and optimized. Methanol has been used as desorption solvent and the extracts were analysed on a reversed-phase octadecyl silica column using 0.02 M phosphate-buffer (pH = 6.02) acetonitrile (65 : 35 v/v) as the mobile phase and the effluents were measured at 202 nm with ultraviolet detector. The relative standard deviation (RSD%) of the method was investigated at three concentrations (25, 50, and 200 ng/mL) and was in the range of 3.98–9.83%(n=6)for 50 ng/mL. The calibration curves obtained for studied drugs show reasonable linearity(R2>0.99)and the limit of detection(LODs)ranged between 2 and 7 ng/mL. Finally, the proposed method has been effectively employed in extraction and determination of the drugs in biological and environmental samples.

scholarly journals Portable Chemiluminescence-Based Lateral Flow Assay Platform for the Detection of Cortisol in Human Serum

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 191
Author(s):  
Hyun Tae Kim ◽  
Enjian Jin ◽  
Min-Ho Lee
Keyword(s):  
Human Serum ◽  
Limit Of Detection ◽  
Serum Cortisol ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Nanoparticle Probes ◽  
Luminescent Signal ◽  
Microplate Reader ◽  
Sensitive Determination

In this study, we developed the portable chemiluminescence (CL)-based lateral flow assay (LFA) platform for the detection of cortisol in human serum. Cortisol is well-known as a stress hormone due to its high relevancy for human mental and physical health, such as hypertension or depression. To date, a number of optical devices have provided the sensitive determination of levels of analytes. However, this modality type still requires costly optical modules. The developed CL platform is simply composed of two detection modules along with a loading part for the LFA strip. The LFA membrane contains gold nanoparticle probes conjugated with antibodies against cortisol and horseradish peroxidase (HRP), which can also efficiently increase the luminescent signal by providing many areas for anti-cortisol antibody and HRP. The measured voltage signals coming from the photodiode in a CL reader were compared with a standard microplate reader for the evaluation of accuracy. The linear range observed for cortisol was measured to be 0.78–12.5 μg/dL (R2 = 0.99) with a limit of detection (LOD) of 0.342 μg/dL. In addition, the CL-LFA reader showed a high correlation (R2 = 0.96) with the standard cortisol console (COBAS 8000, Roche), suggesting that our developed CL-based LFA platform can be usable in situ.

scholarly journals Development of a Novel, Rapid IntegratedCryptosporidium parvum Detection Assay

2000 ◽  
Vol 66 (7) ◽  
pp. 2711-2717 ◽  
Author(s):  
Diane Kozwich ◽  
Kristine A. Johansen ◽  
Keli Landau ◽  
Christopher A. Roehl ◽  
Sam Woronoff ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Detection System ◽  
Immunomagnetic Separation ◽  
Immunofluorescence Assay ◽  
Lateral Flow ◽  
Reverse Transcription Pcr ◽  
Extraction And Purification ◽  
Flow Detection ◽  
Solid Phase Material

ABSTRACT The aim of this study was to develop a reverse transcription-PCR assay and lateral flow detection protocol for specific identification of Cryptosporidium parvum. The method which we developed is sensitive and specific and has a low limit of detection. In our protocol a solid phase material, the Xtra Bind Capture System, was used for extraction and purification of double-stranded RNA (dsRNA) specific for C. parvum. The Xtra Bind Capture System interfaced with pellets concentrated from water samples collected with previously developed filtration devices. The pellets were resuspended in reagent water (final volume, 0.5 ml), and an equal amount of rupture buffer and the Xtra Bind Capture System was added to the resuspended pellet mixture. The dsRNA target sequences in a 0.5-ml portion were captured by the solid phase material via hybridization. The debris and potential inhibitors were removed by washing the Xtra Bind material several times with buffer. The Xtra Bind material with its bound dsRNA was added directly to an amplification reaction mixture, and the target was amplified without elution from the Xtra Bind material. A PCR was performed in the presence of the Xtra Bind Capture System, which resulted in robust amplification of the target. The detection system which we used was adapted from lateral flow chromatography methods typically used for antigen-antibody reactions. The result was a colored line that was visible if the organism was present. When this method was used, we were able to reproducibly and correctly identify 10 oocysts added to 0.5 ml of reagent water. When the protocol was evaluated with a small set of environmental samples, the level of detection was as low as 1 oocyst/liter. The total time from resuspension of the pellet to detection was about 3 h, which is considerably less than the 5 h required for immunomagnetic separation followed by an indirect immunofluorescence assay and microscopy.

scholarly journals Experiments And Simulations of Thermometric Lateral Flow Immunoassay For Point-of-Care Testing

2021 ◽  
Author(s):  
Terumitsu Azuma ◽  
Yuen Yung Hui ◽  
Oliver Y. Chen ◽  
Yuh-Lin Wang ◽  
Huan-Cheng Chang
Keyword(s):  
Laser Power ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Lateral Flow ◽  
Detection Sensitivity ◽  
Lateral Flow Immunoassay ◽  
Point Of Care Testing ◽  
Incident Laser Power ◽  
Latex Beads ◽  
Fold Reduction

Abstract Temperature sensing is a promising method of enhancing the detection sensitivity of lateral flow immunoassay for point-of-care testing. A temperature increase of more than 100 °C can be readily achieved by photoexcitation of reporters like gold nanoparticles (GNPs) or colored latex beads (CLBs) on the strips with a laser power below 100 mW. Despite its promise, processes involved in the photothermal detection have not yet been well-characterized. Here, we provide a fundamental understanding of this thermometric assay by combining experiments and simulations using non-fluorescent CLBs as the reporters deposited on nitrocellulose membrane. By measuring the dependence of temperature rises on the number density of membrane-bound CLBs, we determined a 1.5-fold enhancement of the light absorption at 520 nm by the beads (diameter of 0.4 μm). The enhancement, however, was compromised by a 5-fold reduction of the incident laser power due to multiple scattering of the light in this highly porous medium. The limit of detection was measured to be 1 × 105 particles/mm2. In line with previous studies using GNPs as the reporters, the CLB-based thermometric assay provides a 10× higher sensitivity than color visualization, as demonstrated with the immunoassay for nucleocapsid proteins of the SARS-CoV-2 virus.

Magnetic mixed hemimicelle solid-phase extraction based on mixed hemi-/ad-micelle SDS-coated magnetic nanoparticles Fe2-xAlxO3 (x = 0.4) for the fluorimetric determination of carvedilol in biological samples

2017 ◽  
Vol 95 (5) ◽  
pp. 512-519 ◽  
Author(s):  
Juanli Du ◽  
Hao Wu ◽  
Xiaohui Du ◽  
Zhimin Zhao ◽  
Xin Zhao ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Solid Phase Extraction ◽  
Biological Samples ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Phase Extraction ◽  
Fluorimetric Determination ◽  
First Time ◽  
Efficient Adsorbent

Mixed hemi-/ad-micelle SDS-coated magnetic nanoparticles (Fe2-xAlxO3 (x = 0.4)) were used as an efficient adsorbent for the extraction and preconcentration of carvedilol (CVD) based on magnetic mixed hemimicelle solid-phase extraction. The Fe2-xAlxO3 magnetic nanoparticles not only have better stability and resistance to acidity, as well as alkalinity, but also are easy to prepare, inexpensive, and environmentally friendly. Several parameters that affected the extraction efficiency were investigated, including the type and volume of desorption solvent, extraction and desorption times, pH of the solution, zeta potential, and amounts of adsorbent and surfactant. Under the optimized extraction conditions, the developed method showed good linearity (R2 = 0.9998) within the range of 0.02–2.7 ng mL−1, and the limit of detection was 0.009 ng mL−1. The spiked recoveries of CVD in urine and plasma samples ranged from 101.50% to 111.00%. To the best of our knowledge, this is the first time that a mixed hemi-/ad-micelle solid-phase extraction method based on magnetic separation and nanoparticles has been used as a simple and sensitive method for the monitoring of CVD in biological samples.

Validation of a Rapid Lateral Flow Test for the Simultaneous Determination of β-Lactam Drugs and Flunixin in Raw Milk

2012 ◽  
Vol 75 (7) ◽  
pp. 1270-1277 ◽  
Author(s):  
DAVID DOUGLAS ◽  
KATIE BANASZEWSKI ◽  
RIMA JUSKELIS ◽  
FADWA AL-TAHER ◽  
YANG CHEN ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Limit Of Detection ◽  
Agricultural Practices ◽  
Raw Milk ◽  
Lateral Flow ◽  
Penicillin G ◽  
Screening Programs ◽  
Flow Test ◽  
Lateral Flow Test

β-Lactam antibiotics are the most commonly used drugs on dairy farms. β-Lactam residues in milk are kept out of the human milk supply with good agricultural practices and mandatory truck screening performed by the dairy industry under Appendix N of the Pasteurized Milk Ordinance. Flunixin, a nonsteroidal and anti-inflammatory drug, appears in dairy cattle tissue residues with a frequency similar to the occurrence of penicillin G. This creates concern that flunixin residues could be in milk and would go undetected under current milk screening programs. A single test that combines mandatory β-lactam screening with voluntary flunixin screening is an economical approach for monitoring and controlling for potential flunixin or 5-hydroxyflunixin, the primary flunixin metabolite marker in milk. The objective of this study was to validate a β-lactam and flunixin rapid lateral flow test (LFT) and compare the results obtained with a liquid chromatography-triple quadrupole tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of flunixin and 5-hydroxyflunixin in raw milk with a limit of detection of <1 ppb, equivalent to 1 ng/ml. Using the LFT, three combined manufactured lots of test strips detected penicillin G at 2.0 ppb, ampicillin at 6.8 ppb, amoxicillin at 5.9 ppb, cephapirin at 13.4 ppb, ceftiofur (total metabolites) at 63 ppb, and 5-hydroxyflunixin at 1.9 ppb at least 90% of the time with 95% confidence. The LFT also detected incurred flunixin milk samples that were analyzed with the LC-MS/MS and diluted to tolerance in raw milk. The detection levels for the LFT are lower than the U.S. safe levels or tolerances and qualify the test to be used in compliance with U.S. milk screening programs.

SERUM TRIIODOTHYRONINE DETERMINATION BY SATURATION ANALYSIS

1973 ◽  
Vol 72 (4) ◽  
pp. 714-726 ◽  
Author(s):  
A. Burger ◽  
B. Miller ◽  
C. Sakoloff ◽  
M. B. Vallotton
Keyword(s):  
Ionic Strength ◽  
Limit Of Detection ◽  
Improved Method ◽  
Accuracy Of Measurement ◽  
Tracer Amount ◽  
The Mean ◽  
Physiological Values ◽  
Hyperthyroid Patients ◽  
Solvent Blank

ABSTRACT An improved method for the determination of serum triiodothyronine (T3) has been developed. After addition of a tracer amount of the hormone, T3 was extracted from 1 ml serum under conditions of pH and ionic strength which favoured T3 extraction (89%) over thyroxine (T4) extraction (58%). Chromatography of the extracted material on Sephadex LH-20 separated T3 completely from residual T4. The T3 eluate was dried, then re-dissolved in 0.5 ml NaOH 0.04 n. To 0.2 ml duplicate aliquots, a standard amount of TBG was added for the competitive protein analysis. After one hour incubation at 4°C, separation of bound from free T3 was achieved on small Sephadex G-25 columns. Overall recovery was 67 ± 10.8% and correction for the loss was made. The solvent blank was 37 ± 27 (sd) ng/100 ml. Accuracy of measurement of known quantities of T3 added to serum was 98.4%. The coefficient of variation within the assay was 6.2% and between the assays it was 11.4%. The limit of detection (0.1 ng) corresponded to a concentration of 25 ng/100 ml. T4 added to serum did not interfere with T3 determination until high non-physiological values were reached. The mean ± sd serum T3 in 54 euthyroid subjects was 153 ± 58 ng/100 ml and in 24 hyperthyroid patients it was 428 ±186 ng/100 ml; 4 out of the 24 hyperthyroid values were within 2 sd of the mean euthyroid group. All the values found in the euthyroid group were well above the limit of detection of the method.

Spectrophotometeric Determination of Trifluoperazine HCL in Pure Forms and Pharmaceutical Preperations

2017 ◽  
Vol 9 (5) ◽  
Author(s):  
Mohammad Hamzah Hamzah ◽  
Rawa M M Taqi ◽  
Muna M. Hasan ◽  
Raid J. M. Al-Timimi
Keyword(s):  
Standard Method ◽  
Limit Of Detection ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Oxidizing Agent ◽  
Optimum Conditions ◽  
Limit Of Quantification ◽  
Cerium Ion ◽  
Blank Solution

A simple and accurate spectrophotometric method for the determination of Trifluoperazine HCl in pure and dosage forms was developed. The method is based on the reaction between Trifluoperazine HCl and p-chloroaniline in the presence of cerium ion as oxidizing agent which lead to the formation of violate color product that absorbed at a maximum wavelength 570nm while the blank solution was pink. Under the optimum conditions a linear relationship between the intensity and concentration of TRF in the range 4-50μg/ml was obtained . The molar absorptivity 3.74×103 L.mol-1.cm-1 , Limit of detection (2.21μg/ml), while limit of quantification was 7.39μg/ml. The proposed analytical method was compared with standard method using t-test and F-test , the obtained results shows there is no significant differences between proposed method and standard method. Based on that the proposed method can be used as an alternative method for the determination of TRF in pure and dosage forms.

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