title: Tunable Plasmonic Nanohole Arrays Actuated by a Thermoresponsive Hydrogel Cushion.
abstract: New plasmonic structure with actively tunable optical characteristics based on thermoresponsive hydrogel is reported. It consists of a thin, template-stripped Au film with arrays of nanoholes that is tethered to a transparent support by a cross-linked poly(N-isopropylacrylamide) (pNIPAAm)-based polymer network. Upon a contact of the porous Au surface with an aqueous environment, a rapid flow of water through the pores enables swelling and collapsing of the underlying pNIPAAm network. The swelling and collapsing could be triggered by small temperature changes around the lower critical solution temperature (LCST) of the hydrogel. The process is reversible, and it is associated with strong refractive index changes of Δn∼ 0.1, which characteristically alters the spectrum of surface plasmon modes supported by the porous Au film. This approach can offer new attractive means for optical biosensors with flow-through architecture and actively tunable plasmonic transmission optical filters.
authors.affiliation: Biosensor Technologies, AIT-Austrian Institute of Technology, Muthgasse 11, Wien, Austria; Centre for Biomimetic Sensor Science, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Drive, Singapore 637553, Singapore.
authors.forename: Nityanand
authors.initials: N
authors.lastname: Sharma
authors.affiliation: Biosensor Technologies, AIT-Austrian Institute of Technology , Muthgasse 11, Wien, Austria.
authors.forename: Hamid
authors.initials: H
authors.lastname: Keshmiri
authors.affiliation: Institute of Materials Research & Engineering, ASTAR, Singapore , 2 Fusionopolis Way, #08-03, Innovis, Singapore 138634, Singapore.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Institute of Materials Research & Engineering, ASTAR, Singapore , 2 Fusionopolis Way, #08-03, Innovis, Singapore 138634, Singapore.
authors.forename: Ten It
authors.initials: TI
authors.lastname: Wong
authors.affiliation: Biosensor Technologies, AIT-Austrian Institute of Technology, Muthgasse 11, Wien, Austria; Macromolecular Chemistry, Department Chemistry-Biology, University of Siegen, Adolf-Reichwein-Strasse 2, Siegen 57076, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Petri
authors.affiliation: Macromolecular Chemistry, Department Chemistry-Biology, University of Siegen , Adolf-Reichwein-Strasse 2, Siegen 57076, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Jonas
authors.affiliation: Centre for Biomimetic Sensor Science, School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Drive, Singapore 637553, Singapore.
authors.forename: Bo
authors.initials: B
authors.lastname: Liedberg
authors.affiliation: Biosensor Technologies, AIT-Austrian Institute of Technology , Muthgasse 11, Wien, Austria.
authors.forename: Jakub
authors.initials: J
authors.lastname: Dostalek