Poly(N-Isopropylacrylamide) Polymer Brush Functionalized Nanostructures as Thermo-Responsive Gating Systems for Protein Transportation
Licentiate thesis, 2021

Controlling molecule translocation through nanosized gaps is of great interest in novel systems for single molecule analysis and biomolecular membranes. The molecular gating property of thermo-responsive end-grafted poly(N-isopropylacrylamide) (PNIPAM) polymer brushes on well-shaped gold-silica nanostructures is intended to be investigated for controlled protein transportation via extinction spectroscopy and fluorescence microscopy methods below and above PNIPAM lower critical solution temperature (LCST; 32 °C in water). Polymer brushes are prepared via Activators Regenerated by Electron Transfer Atom Transfer Radical Polymerization (ARGET-ATRP) by employing Bis[2-(2- bromoisobutyryloxy)undecyl] disulfide (DTBU) and its thiol (TBU) equivalent as initiators for the reaction. Variation of PNIPAMreaction time/solvent constituency during the polymerization, results in different swollen/collapsed polymer brush thicknesses, indicated by the plasmonic shifts in extinction spectroscopy and surface plasmon resonance experiments. By having sufficient polymer thickness and grafting density for, e.g. 80-90 nm, nanowells, polymer conformational change below and above LCST, allows controlled gating of these nanostructures. This feature was employed for protein transportation through the polymer brush interface in and out of the fabricated nanowell according to its plasmonic activity. In addition, we investigated molecular gating of fluorescently labelled protein transportation by complimentary fluorescence microscopy measurements.

biomolecule transportation

thermo-responsive polymers

Poly(N-Isopropylacrylamide)

surface plasmon resonance

polymer brushes

fluorescence microscopy

Author

Justas Svirelis

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Andreas Dahlin Group

SIMONANO (Single Molecule Analysis in Nanoscale Reaction)

Familjen Erling-Perssons stiftelse, 2018-02-01 -- 2019-12-31.

Subject Categories

Polymer Chemistry

Physical Chemistry

Polymer Technologies

Roots

Basic sciences

Infrastructure

Chalmers Materials Analysis Laboratory

Nanofabrication Laboratory

Licentiatuppsatser vid Institutionen för kemi och kemiteknik, Chalmers tekniska högskola: 01

Publisher

Chalmers University of Technology

Online

Online

More information

Latest update

2/26/2021