Journal article
pH Effect on Protein G Orientation on Gold Surfaces and Characterization of Adsorption Thermodynamics
Langmuir, v 28(17), pp 6928-6934
01 May 2012
PMID: 22497325
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
The pH effect on adsorbed antibody-binding protein (protein G) orientation on gold (Au) and its adsorption thermodynamic characteristics were investigated using quartz crystal microbalance (QCM) and X-ray photoelectron spectroscopy (XPS). The adsorbed protein G orientation was measured by binding response of two antibody-antigen systems: the model bovine serum albumin (BSA) and the foodborne pathogen E. coli 0157:H7. Surface coverage was not significantly affected by pH, but its orientation was. The most properly oriented protein G for antibody binding was achieved at near-neutral pH. Adsorption was verified by XPS measurements using nitrogen (N) 1s, oxygen (0) Is, and Au 4p peak heights. Adsorption energetics were determined by van't Hoff and Langmuir kinetic analyses of adsorption data obtained at 296, 303, and 308 K. Large characteristic entropy change of protein adsorption was observed (Delta S degrees = 0.52 +/- 0.01 kcal/mol.K). The adsorption process was not classical physisorption but exhibited chemisorption characteristics based on significant enthalpy change (Delta H degrees = 25 +/- 6 kcal/mol).
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Details
- Title
- pH Effect on Protein G Orientation on Gold Surfaces and Characterization of Adsorption Thermodynamics
- Creators
- Blake N. Johnson - Drexel UniversityRaj Mutharasan - Drexel University
- Publication Details
- Langmuir, v 28(17), pp 6928-6934
- Publisher
- American Chemical Society; Washington, DC
- Number of pages
- 7
- Grant note
- CBET-0828987 / NSF; National Science Foundation (NSF)
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Chemical and Biological Engineering
- Web of Science ID
- WOS:000303348900026
- Scopus ID
- 2-s2.0-84860490304
- Other Identifier
- 991019170972304721
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InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Web of Science research areas
- Chemistry, Multidisciplinary
- Chemistry, Physical
- Materials Science, Multidisciplinary