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Physics Colloquium - Noah Hensley

Monday, 6 May 2019

Physics Department

Noah Hensley

Department of Physics

University of Otago

"An Inexpensive Nanoparticle-embedded Porous Anodic Alumina Filter for Optical Sensing of Chemicals "

Despite thousands of experimental studies on plasmonic sensing, one of the most commercially successful plasmonic sensing platforms was established over three decades ago and continues to use the simplest plasmonic structure: a thin metallic film coated on a dielectric surface (e.g. Biacore SPR Systems). Manufacturing thin, continuous metallic films on dielectric surfaces is also straight-forward and inexpensive, requiring only a vacuum chamber and pump integrated with a method for evaporation of a metallic source (i.e. thermal heating or plasma sputtering). In this work, porous anodic alumina filters, like those shown in Figures A-B, were coated with nominal silver thicknesses of < 40 nm. The resulting plasmonic structure consists of a distribution of self-assembled silver nanoparticles embedded on the outer and inner surface of the filters as depicted in Figure C. The filters were then loaded into a flow cell and tested for general sensing capabilities using optical transmission spectroscopy (Figure D) while being flushed with varying concentrations of polystyrene sulfonate. The sensitivity of this novel plasmonic sensing platform is shown to be tunable by simply varying deposition thickness. Ideas for future work will also be discussed including the need for collaboration with chemists and biochemists.

WHEN: Monday 6 May 2019
WHERE: Room 314, Science 3 Building
TIME: 3.00 pm–3.30 pm

All interested are welcome to attend

Light refreshments to follow in Common Room