Quick search
Go!

ON USING OF NANO-SIZED ROD-LIKE MAGNETITE PARTICLES FOR DETERMINATION OF BIOLOGICAL BINDING REACTIONS


GABRIELA APREOTESEI 1, RODICA BADESCU 1, OVIDIU ROTARIU 2, LAURA ELENA UDREA 2, VASILE BADESCU 2*
(1) TECHNICAL UNIVERSITY “GH. ASACHI”IAŞI, DEPARTMENT OF PHYSICS, 67 MANGERON BLVD., IAŞI, 700050, ROMANIA (2) NATIONAL INSTITUTE OF RESEARCH AND DEVELOPMENT FOR TECHNICAL PHYSICS, 47 MANGERON BLVD., IAŞI, 700050, ROMANIA *CORRESPONDING AUTHOR: BAV

Issue:

SCSCC6, Volume IX, No. 3

Section:

Volume IX, No. 3 (2008)

Abstract:

Rod-like nano-sized magnetite particles have been prepared by direct precipitation from aqueous solutions in the presence of an external magnetic field. Using these particles we prepared ferrofluids which become birefringent when a magnetic field is applied perpendicular to the optical axis of light impinging the fluid. After switching off the magnetizing field, the birefringence relaxes. We observed that for ferrofluids containing rod-like magnetite nanoparticles the dominant relaxation mechanism is the Brownian motion. Since the constant of the Brownian relaxation time depends on the hydrodynamic size of the particles it can be determined by transient magnetic birefringence measurements.

Considering the fact that biological binding reactions are always connected to changes in the particle size of the reaction components, our work focuses on the monitoring of binding reactions. For the determination of the binding reaction between an antibody and its antigen the magnetic nanoparticles were conjugated with streptavidin. The biotinylated antibody against human immunoglobulin M (hIgM) was attached to the nanoparticles via the binding between biotin and streptavidin. The presented experiments confirm that the determination of the relaxation of the transient field-induced birefringence of rod-like magnetic nanoparticles can be used for the investigation of binding reactions of antibodies to their antigens.

Keywords:

ferrofluids, rod-like nanoparticles, birefringence relaxation, biological binding.

Code [ID]:

CSCC6200809V03S01A0014 [0002412]

Full paper:

Download pdf


Copyright (c) 1995-2007 University of Bacu