Plasmon-enhanced multiphoton polymer crosslinking for selective modification of plasmonic hotspots

ChemRxiv

Abstract

A novel approach to selectively modify narrow sub-areas of metallic nanostructures adjacent to plasmonic hotspots, where strong electromagnetic field amplification occurs upon localized surface plasmon (LSP) excitation, is reported. In contrast to plasmon-driven polymerization, it relies on plasmonically enhanced multiphoton crosslinking (MPC) of polymer chains carrying photoactive moieties. When attached to metallic nanostructures and irradiated with a femtosecond near-infrared beam resonantly coupled with LSPs, the enhanced field intensity locally exceeds the threshold and initiates MPC at plasmonic hotspots. This concept is demonstrated using gold nanoparticle arrays coated with two specifically designed polymers. Local MPC of a poly(N,N-dimethyl acrylamide)-based copolymer with an anthraquinone crosslinker is shown via atomic force microscopy. Additionally, MPC is tested with a thermoresponsive poly(N-isopropyl acrylamide)-based terpolymer. The reversible thermal collapsing and swelling of the MPC-formed hydrogel at specific nanoparticle locations are confirmed by polarization-resolved LSPR spectroscopy. These hybrid metallic/hydrogel materials can be further post-modified offering attractive characteristics for future spectroscopic/bioanalytical applications.

Authors 10

1. Yevhenii M. Morozov

   AIT Austrian Institute of Technology GmbH

   Affiliation as printed

   Austrian Institute of Technology

2. Nestor Gisbert Quilis

   AIT Austrian Institute of Technology GmbH

   Affiliation as printed

   Austrian Institute of Technology

3. Stefan Fossati

   FZU - Institute of Physics of the Czech Academy of Sciences

   Affiliation as printed

   Czech Academy of Sciences, Institute of Physics

4. Laura De Laporte Aachen DWI - Leibniz Institute for Interactive Materials

   DWI – Leibniz Institute for Interactive Materials · RWTH Aachen University

   Affiliation as printed

   DWI – Leibniz Institute for Interactive Materials

   RWTH Aachen University

5. Claudia Gusenbauer

   BOKU University

   Affiliation as printed

   BOKU University

6. Andreas Weber

   BOKU University

   Affiliation as printed

   BOKU University

7. José Luis Toca-Herrera

   BOKU University

   Affiliation as printed

   BOKU University

8. Fiona Wiesner

   University of Siegen

   Affiliation as printed

   University of Siegen

9. Ulrich Jonas

   University of Siegen

   Affiliation as printed

   University of Siegen

10. Jakub Dostálek

    Danube Private University · FZU - Institute of Physics of the Czech Academy of Sciences

    Affiliation as printed

    Czech Academy of Sciences, Institute of Physics

    Danube Private University