Bioassay using blocking temperature: Interparticle interactions between biofunctionalized magnetic nanoparticles conjugated with biotargets
Journal
Applied Physics Letters
Journal Volume
110
Journal Issue
13
Date Issued
2017
Author(s)
Wang C.Y., Yang T.W., Shen D., Chen K.L., Chen J.M., Liao S.H., Chieh J.J., Yang H.C., Wang L.M.
Abstract
This paper reports a bioassay of alpha-fetoprotein (AFP) concentration achieved via the measurement of blocking temperature (TB). Biofunctionalized magnetic nanoparticles (BMNs) consisting of anti-alpha-fetoprotein coated onto dextran-coated magnetic nanoparticles composed of Fe3O4 were prepared and then conjugated with AFP biotargets. It was found that both the saturation magnetization and value of TB increased with the concentration of the associated AFP. Furthermore, the dependence of TB of the samples on magnetic field agreed with the interparticle interaction model. Thus, this study demonstrated a platform to detect biomarkers by characterizing TB with a sensitivity limit of 20 ppb of AFP. The promising results obtained for this bioassay can be attributed to the interparticle interactions and N?el motions of magnetic moments in the BMNs. ? 2017 Author(s).
Subjects
Association reactions; Bioassay; Iron oxides; Magnetic moments; Magnetite; Nanoparticles; Particle interactions; Saturation magnetization; Alpha fetoprotein; Alphafetoprotein (AFP); Blocking temperature; Inter-particle interaction; Magnetic nano-particles; Sensitivity limit; Nanomagnetics
Type
journal article