Synthesis of Polystyrene Nanoparticles with Different
Surface Modification by Emulsion Polymerization and
Measurement of IgG Adsorption and Stability for the
Application in Latex-Protein Complex Based Solid-Phase
Immunoassay
Sanghee Kim
1
( ), Chul Am Kim
2
, Yo Han Choi
1
and Moon Youn Jung
1
1
BioMEMS Team, Electronics and Telecommunication Research Institute, 305-700, Deajeon,
South Korea
2
Flexible Device Team, Electronics and Telecommunication Research Institute, 305-700,
Deajeon, South Korea
E-mail: s-kim@etri.re.kr; Fax: +82-42-860-5608
Received: 12 June 2008 / Revised version: 15 August 2008 / Accepted: 5 October 2008
Published online: 20 October 2008 – © Springer-Verlag 2008
Summary
Unmodified and surface modified polystyrene (PS) nanoparticles with hydrophilic end
group on surface were synthesized by emulsion polymerization for adsorption of
a protein (immunoglobulin G, IgG) by passive adsorption and electrostatic attraction for
the application on solid-phase immunoassay. The presence of formed IgG-PS particle
complex was confirmed by dynamic light scattering (DLS) measurement which shows
the increased size of particle (
≈
178nm and 220nm) after IgG immobilization. Increased
Zeta (ζ) potential from -56.7mV to -3.84mV following the IgG immobilization by
electrostatic attraction also provides the presence of the formed IgG-PS particle
complex. Enzyme-linked immunosorbent assay (ELISA) results demonstrate that the
formed IgG-PS complex was stable and the binding strength between IgG and PS was
maintained after 1 month from initial IgG-PS particle complex formation.
Keywords
emulsion polymerization, surface modification, IgG adsorption, stability, Solid-phase
immunoassay
Introduction
Monodispersed latex nanoparticles are widely used in many field of technology such
as paint coatings, ceramics processing as well as recently many efforts have been
devoted in biomedical applications such as diagnostic test, controlled drug release,
bioaffinity chromatography, biomolecule adsorption, and phagocytosis researches [1-
6]. Several methods for production of the monodispersed latex nanoparticles have
been developed, such as emulsion polymerization, seeded polymerization, emulsifier-
free polymerization, precipitation polymerization, and dispersion polymerization [7].
Polymer Bulletin 62, 23–32 (2009)
DOI 10.1007/s00289-008-1010-y