Title :
Ultrasound enhanced ferrite plating of polymer microspheres for magnetic cellular segregation
Author :
Ojima, Makoto ; Shirasaki, Fumio ; Kitamoto, Yoshitaka ; Abe, Masanori ; Nagahata, Satoru
Author_Institution :
Dept. of Phys. Electron., Tokyo Inst. of Technol., Japan
fDate :
9/1/1999 12:00:00 AM
Abstract :
Polyacrylate microspheres of 4.5 μm diameter were coated with a continuous magnetite layer by ultrasound enhanced ferrite plating, at 70°C from an aqueous solution of FeCl2, utilizing Fe2+→Fe3+ oxidation by NaNO2. The ferrite coatings prepared in this study are ~100 nm in grain size, which is reduced from that (i.e. 300~400 nm) of the coatings prepared by ultrasound enhanced ferrite plating in the authors´ previous study. This owes to improvement in plating conditions. Turbidity analyses revealed that the present ferrite-encapsulated microspheres exhibit lower sedimentation rate and higher efficiency of magnetic separation than the previous ones. This will improve the performance of enzyme immunoassay which has been put to practical use utilizing the partially-ferrite-coated microspheres
Keywords :
biological techniques; biomagnetism; cellular transport; ferrites; magnetic separation; oxidation; polymers; ultrasonic effects; 100 nm; 300 to 400 nm; 4.5 mum; 70 C; Fe2+→Fe3+ oxidation; FeCl2; NaNO2; aqueous solution; biophysical technique; enzyme immunoassay; ferrite coatings; magnetic cellular segregation; partially-ferrite-coated microspheres; plating conditions; polyacrylate microspheres; polymer microspheres; sedimentation rate; turbidity analyses; ultrasound enhanced ferrite plating; Biochemistry; Coatings; Ferrites; Grain size; Iron; Magnetic analysis; Magnetic separation; Oxidation; Polymers; Ultrasonic imaging;
Journal_Title :
Magnetics, IEEE Transactions on
