Nguyen , Quoc Hung
(Bio)Molecular Transport and Recognition in Heavy Ion Track-Etched Polymeric Nanopores.
Technische Universität, Darmstadt
[Ph.D. Thesis], (2013)
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|Item Type:||Ph.D. Thesis|
|Title:||(Bio)Molecular Transport and Recognition in Heavy Ion Track-Etched Polymeric Nanopores|
This thesis is focused on the potential applications of ion track-etched nanopores in polymeric membranes, such as molecular separation, gating and biosensing. The nanopores are fabricated in polyethylene terephthalate (PET) membranes by heavy ion track-etching technique. Ion track technology provides the feasibility to produce membranes with nanopores of desired diameters and geometries. The characterizations of the nanopores are performed by field emission scanning electron microscopy, replica technique and conductometry measurements. Heavy ion irradiation and subsequent track-etching lead to the generation of carboxylic groups (–COOH) on the inner pore walls. At neutral pH, nanopores are cation-selective due to the presence of ionized carboxylate groups (–COO–) on the pore surface. The chemical modification of –COOH groups with amino-terminated molecules switches the surface polarity from negative to positive which in turn flipped the nanopore perm-selective behaviour. Polymeric membranes containing cylindrical nanopores are employed for the transport of ionic organic (bio)molecules through the nanopores. The nanopores have the ability to selectively transport and discriminate the molecules based on their size and charge. For the transport studies main focus is the modulation of pore density, pore diameter, ionic strength of buffer solution and electric field which affect the ionic selectivity and flux of the membrane. Moreover, the polyethyleneimine (PEI) modified pores are also applicable as gate to control the ionic/molecular flux across the membrane. Finally, single (conical and cylindrical) nanopores modified with boronic acid receptor are studied for the molecular recognition of monosaccharides and glycoprotein inside confined geometries. The recognition events are observed by measuring the current – voltage (I–V) curves in an electrolyte solution in the presence of glucose, fructose and glycoprotein separately.
|Place of Publication:||Darmstadt|
|Uncontrolled Keywords:||Track-etched nanopores, nanoporous membranes, molecular separation, chemical modification, biosensors, molecular recognition, molecular gating, current-voltage measurements, selective transport, Poisson and Nernst-Planck equations|
|Classification DDC:||500 Naturwissenschaften und Mathematik > 500 Naturwissenschaften
500 Naturwissenschaften und Mathematik > 540 Chemie
|Divisions:||11 Department of Materials and Earth Sciences > Material Science > Material Analytics|
|Date Deposited:||26 Jun 2013 08:33|
|Last Modified:||26 Jun 2013 08:33|
|Referees:||Ensinger, Prof. Dr. Wolfgang and Neumann, Prof. Dr. Reinhard|
|Refereed:||19 April 2013|