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O: Fachverband Oberflächenphysik
O 57: Plasmonics and Nanooptics II
O 57.9: Vortrag
Mittwoch, 2. April 2014, 18:00–18:15, GER 38
Plasmonic sensing with functionalized hydrogels — •Martin Mesch1, Chunjie Zhang2, Paul V. Braun2, and Harald Giessen1 — 14th Physics Institute and Research Center SCoPE, University of Stuttgart, Germany — 2Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, USA
Plasmonic structures have shown to be a sensitive and versatile tool for different sensing applications. As they inherently respond to anything that changes their dielectric environment, selectivity has to be added separately. In our approach, we utilize a thin layer of a functionalized hydrogel to embed our gold nanostructures. This layer is about 1 micrometer in thickness and consists of a cross-linked polymer network soaked with water.
One possible functionalization makes the hydrogel swell in the presence of glucose. This effect implies a change in the refractive index, and hence is in turn subject to detection via the plasmon resonance shift.
Experiments demonstrate that this system allows for detection of glucose concentrations in the physiological (low millimolar) range, as the hydrogel additionally amplifies the signal, compared to just the refractive index change introduced by glucose in the solution. Response times depend, besides the thickness of the layer, also on the composition of the polymer, and are currently in the order of a few minutes.