Magnetic Particle-based Enzyme Immunoassay Research Articles

A rapid magnetic particle-based enzyme immunoassay for human cytomegalovirus glycoprotein B quantification

Human cytomegalovirus (HCMV) is a herpes virus that can cause severe infections. Still, the available methods for its diagnostic have the main disadvantage of requiring long time to be performed. In this work, a simple magnetic particle-based enzyme immunoassay (mpEIA) for the quantification of glycoprotein B of Human cytomegalovirus (gB-HCMV) in urine samples is proposed. The immunosensor scheme is based on the analyte protein gB-HCMV sandwiched between a primary monoclonal antibody, (MBs-PrG-mAb1), and a secondary anti-gB-HCMV antibody labelled with Horseradish peroxidase (Ab2-HRP) to allow spectrophotometric detection.The mpEIA analytical performance was tested in urine samples, showing a linear dependence between gB-HCMV concentration and the absorbance signal at 450 nm in a range of concentrations from 90 to 700 pg mL−1. The calculated detection limits for gB-HCMV were 90 ± 2 pg mL−1 and the RSD was about 6.7% in urine samples. The immunosensor showed good selectivity against other viruses from Herpesviridae family, namely varicella zoster and Epstein Barr viruses. The recoveries of spiked human urine samples at 0.30–0.50 ng mL−1 concentration levels of gB-HCMV ranged between 91 to 105%. The proposed mpEIA method was validated following the guidelines of the European Medicines Agency (EMEA-2014), and allows rapid, successful and easy quantification of gB-HCMV in urine samples.

Rapid simultaneous extraction and magnetic particle-based enzyme immunoassay for the parallel determination of ochratoxin A, fumonisin B1 and deoxynivalenol mycotoxins in cereal samples

This work describes the development of a rapid method for the extraction and the immunochemical determination of three mycotoxins, deoxynivalenol, fumonisin B1, and ochratoxin A, from cereal samples (wheat and corn flours).

Development of a Magnetic Particle-Based Enzyme Immunoassay for the Determination of Penoxsulam in Water

A competitive enzyme-linked immunoassay (ELISA) for the quantitation of Penoxsulam [2-(2,2-difluoroethoxy)-6-(trifluoromethyl-N-(5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidin-2-yl))benzenesulfonamide] in ground and surface waters was developed. This immunoassay utilizes magnetic particles as the solid phase to which polyclonal rabbit anti-Penoxsulam antibodies are attached. The ELISA has an estimated detection limit of 0.17 ppb (microg/mL) of Penoxsulam in water. Specificity studies indicate that the antibody can distinguish Penoxsulam from its major metabolites and structurally similar pesticides. Interference studies indicate that the ELISA has a wide tolerance of sample pH and salinity and for compounds commonly found in surface and ground waters. The ELISA was shown to compare favorably to LC-MS/MS on ground and surface water samples (r(2) = 0.957). The various studies performed demonstrate the usefulness of the ELISA technique as a rapid and high-throughput analytical method for the cost-effective monitoring of water samples.

Development of a Magnetic Particle-Based Enzyme Immunoassay for the Quantitation of Chlorpyrifos in Water

A competitive enzyme immunoassay for the quantitation of chlorpyrifos in water that utilizes amine-terminated superparamagnetic particles as the solid phase to covalently attach mouse monoclonal anti-chlorpyrifos antibodies was developed. Specificity studies indicate that the monoclonal antibody can distinguish chlorpyrifos from its major degradation products, including 3,5,6-trichloro-2-pyridinol, and structurally similar pesticides. The immunoassay has an estimated limit of detection of 0.10 ng/mL in water and compares favorably with traditional chromatographic methods when water samples are analyzed by both methods (r = 0.985). Within- and between-assay percent coefficient of variation values are <13%, and recovery of chlorpyrifos from water averaged 97% across the range of the immunoassay method. Keywords: Chlorpyrifos; immunoassay; ELISA; organophosphate; monoclonal antibody; insecticide; water

Determination of Trace Atrazine Levels in Water by a Sensitive Magnetic Particle-Based Enzyme Immunoassay

Atrazine is a pre- and post-emergence selective herbicide specific for broad-leaved weeds and grasses. Although extensively applied in the United States, its use in Europe is limited and restricted. European drinking water regulations are strict: allowable atrazine contamination levels are 100 parts per trillion (ppt, ng/L). As a result of European regulations, increased method sensitivity is needed to detect atrazine-contaminated water supplies. A sensitive and rapid enzyme immunoassay using specific atrazine antiserum covalently coupled to a magnetic particle solid phase has been developed for the quantitation of atrazine in water at parts per trillion levels. The immunoassay provides accurate detection to as low as 15 ppt of atrazine directly from a 250 μL water sample. Recovery from water samples without sample pretreatment averaged 100% and compared favorably to samples with GC/MS results (r = 0.993). The immunoassay represents a valuable method to detect trace amounts of atrazine in ground, surface, and drinking waters. Keywords: Atrazine; immunoassay; ELISA; triazine; herbicide

Determination of Pentachlorophenol in Water and Soil by a Magnetic Particle-Based Enzyme Immunoassay

A competitive enzyme immunoassay using specific pentachlorophenol (PCP) antiserum covalently coupled to a magnetic particle solid phase has been developed for the detection of PCP in water and soil. The immunoassay allows the quantification of PCP from 100 ppt(parts per trillion, ng/L) in water and 100 ppb (parts per billion, mg/L) in soil. Spike recovery from water samples with no sample pretreatment and from various soil types following a simple extraction technique averaged 105% and 94%, respectively. The method compares favorably with GC/MS and HPLC measurements in water (r=0.980) and soil (r=0.996) samples.

Determination of chlorothalonil in water and agricultural products by a magnetic particle-based enzyme immunoassay

A competitive enzyme immunoassay for the quantitation of chlorothalonil in water and agricultural products was developed. This immunoassay utililizes amine-terminated superparamagnetic particles as the solid phase to covalently attach polyclonal rabbit anti-chlorothalonil antisera. Specificity studies indicate that the antibody can distinguish chlorothalonil from its major metabolites and structurally similar pesticides. The immunoassay has a detection limit of 0.07 parts per billion (ppb, ng/mL) in water. The assay compares favorably with GC measurements when water samples are analyzed (r = 0.984). Studies indicate that the assay can potentially be used to analyze agricultural products after homogenization with acetone (detection limit of 20 ppb for celery) or to analyze dislodgable residues after a methanol surface wash (detection limit of 5 ppb for snow pea pods).

Development and evaluation of a magnetic particle based enzyme immunoassay for aldicarb, aldicarb sulfone and aldicarb sulfoxide

A magnetic particle based solid-phase enzyme linked immunosorbent assay (ELISA) for the determination of parts per billion levels of aldicarb and its sulfoxide and sulfone metabolites in water was developed. Sensitivity is estimated at 250 ppt based on a 90% B/Bo with results available in less than one hour. Photometric analysis of the final colored reaction was made using a specially designed microprocessor controlled photometer with extensive data reduction capability. Assay interference was not seen over a wide pH range and with high concentrations of inorganic ions. Results were shown to qualitatively correlate with HPLC and GC using a positive cutoff of 0.5 ppb. Quantitative comparisons were difficult due to the variable reactivities of aldicarb and its metabolites. This rapid, convenient method would be an excellent screening tool for large numbers of water samples with the potential for application in other matrices, as illustrated by a study on lemonade.