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

Volume

35

Issue

5

fYear

1999

fDate

9/1/1999 12:00:00 AM

Firstpage

4118

Lastpage

4120

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;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.800774

Filename

800774