Publication: Spectroscopic studies of conformational changes of β-lactoglobulin adsorbed on gold nanoparticle surfaces
Issued Date
2014-02-15
Resource Type
ISSN
10957103
00219797
00219797
Other identifier(s)
2-s2.0-84888780182
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Mahidol University
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SCOPUS
Bibliographic Citation
Journal of Colloid and Interface Science. Vol.416, (2014), 184-189
Suggested Citation
Thunnalin Winuprasith, Manop Suphantharika, David Julian McClements, Lili He Spectroscopic studies of conformational changes of β-lactoglobulin adsorbed on gold nanoparticle surfaces. Journal of Colloid and Interface Science. Vol.416, (2014), 184-189. doi:10.1016/j.jcis.2013.11.006 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/33572
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Title
Spectroscopic studies of conformational changes of β-lactoglobulin adsorbed on gold nanoparticle surfaces
Abstract
In this work, we investigated the conformational changes of a globular protein (β-lactoglobulin, β-lg) coated on the surface of 200. nm gold nanoparticles (GNPs) using a number of analytical techniques: dynamic light scattering (DLS); particle electrophoresis (ζ-potential); localized surface plasmon resonance (LSPR) spectroscopy; transmission electron microscopy (TEM); and surface-enhanced Raman scattering (SERS). The β-lg (pH 3) concentration had a pronounced effect on the aggregation and surface charge of β-lg-coated GNPs. The surface charge of GNPs changed from negative to positive as increasing amounts of β-lg molecule were added, indicating that the globular protein molecules adsorbed to the surfaces of the particles. Extensive particle aggregation occurred when β-lg did not saturate the GNP surfaces, which was attributed to electrostatic bridging flocculation. Modifications in LSPR and SERS spectra after addition of β-lg to the GNP suspensions supported the adsorption of β-lg to the particle surfaces. Moreover, SERS highlighted the importance of a number of specific molecular groups in the binding interaction, and suggested conformational changes of the globular protein after adsorption. This research provides useful information for characterizing and understanding the interactions between globular proteins and colloidal particles. © 2013 Elsevier Inc.