Novel Functionalized Nanopores for Plasmonic Sensing
Doctoral thesis, 2021
This thesis presents different types of nanoplasmonic sensing platforms, each with a unique geometry in which biomolecules can be probed through plasmonic read out. Two of the structures were fabricated by short-range ordered colloidal self-assembly and etching of the solid support underneath a nanohole array. The structures are denoted as ‘nanocaves’ and ‘nanowells’ depending on the degree of anisotropy. By suitable surface functionalization, the geometry of the plasmonic nanocavities was utilized for location-specific detection of proteins. In addition, nanowells were employed to investigate curvature-dependent biomolecular interactions.
We have also developed subwavelength apertures in optically thin silicon nitride membranes covered with continuous metal films, referred to as solid-state ‘nanopores’. Plasmonic nanopores in suspended metal-insulator-metal films were fabricated in short-range ordered and long-range ordered arrays using short-range ordered colloidal self-assembly and electron beam lithography, respectively. Both methods prevent the metal from ending up on the silicon nitride walls which is of paramount importance for plasmonic properties and selective chemical functionalization. Preparing nanopores with identical structure but different aperture ordering provides the opportunity to understand how aperture ordering influences plasmonic response, particularly with respect to the nature of far field spectral features. Long-range ordered vs. short-range ordered nanopores exhibit similar optical properties with only a few differences in the plasmonic response.
By appropriate material-specific modification (thiol and trietoxysilane chemistry) plasmonic nanopores were employed for detection of average sized proteins (~ 60 kg/mol) inside the pores. In addition to nanoplasmonic sensing, we could also construct a credible mimic (in terms of geometry) of nuclear pore complexes, when the size of the solid state nanopores approaches ~ 50 nm. The unique geometry and size of nanopores (diameter ~ 50 nm) opens up the possibility to mimic the geometry of biological nanomachines with integrated optical sensing capabilities.
surface plasmon resonance
nuclear pore complex
electron beam lithography
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Andreas Dahlin Group
Optical properties of plasmonic nanopore arrays prepared by electron beam and colloidal lithography
Nanoscale Advances,; Vol. 1(2019)p. 4282-4289
Nanoplasmonic Sensor Detects Preferential Binding of IRSp53 to Negative Membrane Curvature
Frontiers in Chemistry,; Vol. 7(2019)
Detecting Selective Protein Binding Inside Plasmonic Nanopores: Toward a Mimic of the Nuclear Pore Complex
Frontiers in Chemistry,; Vol. 6(2018)
Nanoplasmonic Sensing Architectures for Decoding Membrane Curvature-Dependent Biomacromolecular Interactions
Analytical Chemistry,; Vol. 90(2018)p. 7458-7466
Fabrication and Characterization of Plasmonic Nanopores with Cavities in the Solid Support
Sensors,; Vol. 17(2017)p. Article no. 1444 -
This thesis explores the use of nanotechnology (a series of nanofabrication techniques) to engineer solid-state nanopores with different geometries and certain optical properties to probe molecular interactions involving proteins. The architecture of the nanopores allows us to study protein behavior when proper surface modification is performed on the nanostructure. Nanopores can act as nanoscale chambers, where proteins bind solely inside the pores if they are properly modified, thereby creating a location-specific sensor. Moreover, there are biological nanopores in the human body that control proteins transport. The geometry of the engineered nanopores can also be utilized to mimic such biological nanomachines to better understand the protein transport mechanisms in the human cells. The research herein is aimed toward developing robust nanostructured platforms to utilize nanoscale geometry in combination with surface chemistry to detect protein molecules and study their behavior.
Other Natural Sciences
Areas of Advance
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5005
Chalmers University of Technology
Lecture hall KE, Kemivägen 4
Opponent: Duncan S. Sutherland