Immuno-magnetic diagnosisof Brucella abortus based on of iron and graphene nanoparticles

Brucella is one of the common diseases between livestock human, which is transmitted to human by livestock. There are many common methods for diagnosing Brucella. But these methods don’t have requisite sensitivity and efficiency. In this study,the iron nanoparticles (MNPs) and graphene nanoparticles(GQD) were synthesized.Polyclonal antibodies against Brucella (800 μgmL-1, 5μL) associated with Nano think acid-probe and 50mg of GQD were conjugated using EDC and NHS linkers. GQD were separated by centrifugation at 8000 rpm, for10 min. Then, the GQDswere washed 3 times with distilled water.Next;MNPs (30mg) were conjugated to antibody by EDC and NHS linkers.The MNP-IgG was separated by magnetic field.Subsequently, the MNP-IgGwere washed 3 times with distilled water. For determining the sensitivity of the method, MNP-IgG (3 mg) and GQDs-IgG(5mg) were added to the different concentrations of Brucella (101-108CFU mL-1) at the LB-broth medium for 45 min. The MNP-IgG-Brucella-IgG-GQDs Complex was separated by magnetic field. In order to release the signal probe, the complex was dissolved in 1 mL of0.5M DTT solution at 65 °C. The supernatant was separated and then was read by fluorescencespectrophotometry. The specific of the method was checked at the presence of the different species of the bacteria. Theresults showed that the size of the synthesized MNPand GQDswere 23-35nm and 205-242 nm,respectively. The sensitivity of the method was determined as 102 CFU mL-1.

کلیدواژه ها:

Brucella ، MNP-IgG ، GQDs ، Immuno-magnetic