Magnetic Clustering Effect during the Association of Biofunctionalized Magnetic Nanoparticles with Biomarkers.
We report herein an investigation into dynamic magnetic clustering that occurs during immunoassays as biofunctionalized magnetic nanoparticles (BMNs) become associated with biotargets. We measure the dynamic effective relaxation time τeff(t) and use scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to investigate the C-reactive protein (CRP) as it associates with the BMN Fe3O4-antiCRP to form the magnetic cluster Fe3O4-antiCRP-CRP. The results indicate that τeff(t) increases with increasing association time. In addition, the ration Δτeff/τ0 as a function of CRP concentration follows a characteristic logistic function, which provides a basis for estimating the quantity of biomolecules with a detection sensitivity close to 0.1 ppm. After the association, SEM and TEM images show that CRP and Fe3O4-antiCRP conjugate to form Fe3O4-antiCRP-CRP clusters hundreds of nanometers in size. The SEM and TEM images provide direct evidence of the formation of magnetic clustering.
Department of Physics, National Chung Hsing University, Taichung, Taiwan.
Kuen-Lin
KL
Chen
Department of Materials Engineering, Kun Shan University, Tainan, Taiwan.
Jean-Hong
JH
Chen
Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, Taiwan.
Su-Hsien
SH
Liao
Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, Taiwan.
Jen-Je
JJ
Chieh
Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, Taiwan.
Herng-Er
HE
Horng
Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei, Taiwan.
Li-Min
LM
Wang
Department of Electro-optical Engineering, Kun Shan University, Tainan, Taiwan.
Hong-Chang
HC
Yang
D015415:Biomarkers / Q000737:chemistry / Q000378:metabolism; D002097:C-Reactive Protein / Q000737:chemistry / Q000378:metabolism*; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D006801:Humans; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010316:Particle Size
D015415:Biomarkers; D058185:Magnetite Nanoparticles; D002097:C-Reactive Protein; D052203:Ferrosoferric Oxide