Article

In Situ Monitoring of Protein Adsorption on a Nanoparticulated Gold Film by Attenuated Total Reflection Surface-Enhanced Infrared Absorption Spectroscopy

State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China.
Langmuir (Impact Factor: 4.38). 05/2012; 28(25):9460-5. DOI: 10.1021/la300819u
Source: PubMed

ABSTRACT In situ surface enhanced infrared absorption spectroscopy (SEIRAS) with an attenuated total reflection (ATR) configuration has been used to monitor the adsorption kinetics of bovine hemoglobin (BHb) on a Au nanoparticle (NP) film. The IR absorbance for BHb molecules on a gold nanoparticle film deposited on a Si hemispherical optical window is about 58 times higher than that on a bare Si optical window and the detection sensitivity has been improved by 3 orders of magnitude. From the IR signal as a function of adsorption time, the adsorption kinetics and thermodynamics can be explored in situ. It is found that both the electrostatic interaction and the coordination bonds between BHb residues and Au NP film surface affect the adsorption kinetics. The maximum adsorption can be obtained in solution pH 7.0 (close to the isoelectric point of the protein) due to the electrostatic interaction among proteins. In addition, the isotherm of BHb adsorption follows well the Freundlich adsorption model.

0 Followers
 · 
73 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Recent advances in nanotechnology offer great opportunities for the application of technogenic nanoparticles (NPs) in biology and medicine. The size of NPs enables their penetration into almost all organs, tissues, cells and cell organelles. The interaction of NPs with proteins can in certain cases lead to structural modification of the protein molecules, resulting in the exposure of previously hidden peptide epitopes on the protein surface and the acquisition of new, nonphysiological functions by the proteins. The adsorption of proteins and peptides on the surface of the NPs can result in an increase in the local concentration of protein molecules, and this can lead to structural and functional changes in the molecules due to increased avidity. The interaction of NPs with proteins and peptides can also induce cooperative effects, thereby changing the rate of formation of fibrillar aggregates of proteins or stimulating the formation of amorphous aggregates of NPs and biomolecules. A thorough understanding of the molecular mechanisms of nano-bio interactions is obviously necessary for the further development of a wide range of applications of nanotechnology. The present review addresses recent advances in the study of the molecular mechanisms of interaction of proteins and peptides with NPs, as well as the possible structural, functional, and toxic effects of these interactions. The data presented in the review may be useful for an analysis of the possible effects of the biomolecular interaction with technogenic NPs.
    Nanotechnologies in Russia 11/2013; 8. DOI:10.1134/S1995078013060116
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Interactions of cytochrome c (cyt c) with cardiolipin (CL)-containing membranes have been revealed to play an important role in inducing early apoptosis. In this paper, we studied the interaction of cyt c with solid-supported CL-containing lipid bilayers by a lable-free spectroelectrochemistry method. The biomimetic membrane was fabricated by fusing cardiolipin-phosphatidylcholine (CL_PC, 1:4) vesicles onto the hydrophobic surface of a pre-adsorbed 1-dodecanethiol (DT) on a gold electrode (CL_PC/DT/Au). The adsorption of cyt c onto the CL_PC/DT/Au was in-situ studied by cyclic voltammetry (CV) and surface-enhanced Infrared adsorption spectroscopy (SEIRAS). The electrochemistry of Cyt c/CL_PC/DT/Au exhibits the formal potential (Ef) at 0.43 V (vs. SHE), a positive shift of 190 mV as compared to that of native cyt c adsorbed at the mercaptoundecanoic acid-modified gold electrode (Cyt c/MUA/Au). The potential-induced SEIRA difference spectroscopy discloses that cyt c was loosely adsorbed onto CL_PC/DT/Au in a different orientation, and underwent a new β-sheet formation relative to native cyt c adsorbed onto MUA/Au. It could be the enhanced hydration change of CL-bound cyt c (Fe3+) upon oxidization and reduction and the different adsorption orientation that determine the positive shift in the formal potential of CL-bound cyt c.
    The Journal of Physical Chemistry C 02/2015; DOI:10.1021/jp507225m · 4.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This work presents the design and characterization of an optimized attenuated total reflection (ATR) microfluidic cell to assess intrinsic kinetic parameters of reactions at the liquid/solid interface under chemical control. A theoretical and computational investigation of convection, diffusion, and adsorption is presented. Transport dynamics in transient-flow experiments is characterized by a convective and diffusive mass transport of the solution species to the surface of the ATR crystal. Criteria to determine the mass transport limitations of the adsorption process are presented as a function of the Damköhler and Biot numbers. The CO adsorption on a thin film of platinum is studied in order to validate the model.
    Chemical Engineering Journal 05/2014; 243:197–206. DOI:10.1016/j.cej.2014.01.001 · 4.06 Impact Factor