Title :
A Ferrofluid Immunoassay Based on Magnetic Field-Induced Birefringence
Author :
Ku, Ben Y. ; Horsley, David A.
Author_Institution :
Univ. of California, Davis
Abstract :
An immunoassay is described based on optical detection of the frequency-dependent magnetic relaxation signal in a ferrofluid. The binding of antibodies to magnetic nanoparticles in the ferrofluid causes changes in the magnetic relaxation signal due to an increase in the nanoparticle diameter. The addition of 16.1 ng of antibodies to a 100 mul ferrofluid sample results in an increase in average nanoparticle diameter from 109 nm to 250 mn.
Keywords :
biomedical measurement; biosensors; birefringence; magnetic fields; magnetic fluids; magnetic relaxation; nanobiotechnology; nanoparticles; ferrofluid immunoassay; frequency-dependent magnetic relaxation signal; magnetic field-induced birefringence; magnetic nanoparticles; nanoparticle diameter; optical detection; Birefringence; Immune system; Magnetic field measurement; Magnetic fields; Magnetic materials; Magnetic separation; Nanoparticles; Optical refraction; Optical sensors; Optical variables control;
Conference_Titel :
Sensors, 2007 IEEE
Conference_Location :
Atlanta, GA
Print_ISBN :
978-1-4244-1261-7
Electronic_ISBN :
1930-0395
DOI :
10.1109/ICSENS.2007.4388595
