Immobilization of hairpin deoxyribose nucleic acid aptamers on gold: surface folding dictated analyte-binding performance and electron transfer kinetics

Resource type
Thesis type
(Thesis) M.Sc.
Date created
2011-11-28
Authors/Contributors
Author: Ho, Cassie
Abstract
The performance of hairpin aptamer-based electrochemical sensors is highly dependent on the structural nature of the DNA aptamer monolayer immobilized on the electrode surface. It was discovered in this study that an increase of the surface density of aptamers on the electrode does not improve the sensor’s sensitivity, but in fact diminishes its response to the analyte. The electron transfer kinetics between the redox centre (methylene blue) and the gold electrode strongly depend on the surface density (and thus the folding state) of the hairpin DNA aptamers, and shows a unique two-stage behaviour, i.e., a relatively fast process (irrespective of the surface density) at low surface density followed by a sharp decrease in the apparent rate constants (when the surface density increases).
Document
Identifier
etd6921
Copyright statement
Copyright is held by the author.
Permissions
The author granted permission for the file to be printed, but not for the text to be copied and pasted.
Scholarly level
Supervisor or Senior Supervisor
Thesis advisor: Yu, Hua-Zhong
Member of collection
Attachment Size
etd6921_CHo.pdf 2.82 MB