Periodic protein adsorption at the gold/biotin aqueous solution interface: evidence of kinetics with time delay.
An oscillatory molecular adsorption pattern of the protein neutravidin from aqueous solution onto gold, in presence of a pre-deposited self assembled mono-molecular biotin film, is reported. Real time surface Plasmon resonance sensing was utilized for evaluation of the adsorption kinetics. Two different fractions were identified: in the initial phase, protein molecules attach irreversibly onto the Biotin ligands beneath towards the jamming limit, forming a neutravidin-biotin fraction. Afterwards, the growth rate exhibits distinct, albeit damped adsorption-desorption oscillations over an extended time span, assigned to a quasi reversibly bound fraction. These findings agree with, and firstly confirm a previously published model, proposing macro-molecular adsorption with time delay. The non-linear dynamic model is applicable to and also resembles non-damped oscillatory binding features of the hetero-catalytic oxidation of carbon monoxide molecules on platinum in the gas phase. An associated surface residence time can be linked to the dynamics and time scale required for self-organization.
Universidade Federal de Campina Grande, Center for Electrical Engineering and Informatics, Department of Electrical Engineering, Campina Grande, Paraiba, Brazil.
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H
Neff
Universidade Federal de Campina Grande, Center for Science and Technology, Department of Chemical Engineering, Campina Grande, Paraiba, Brazil.
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HM
Laborde
Universidade Federal de Campina Grande, Center for Electrical Engineering and Informatics, Department of Electrical Engineering, Campina Grande, Paraiba, Brazil.
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Lima