4 years ago

Surface Energy-Controlled SERS Substrates for Molecular Concentration at Plasmonic Nanogaps

Surface Energy-Controlled SERS Substrates for Molecular Concentration at Plasmonic Nanogaps
Xiaofei Xiao, ChaeWon Mun, Dong-Ho Kim, Sung-Gyu Park, Stefan A. Maier, Sunho Kim, Avi Braun, Vincenzo Giannini
Positioning probe molecules at electromagnetic hot spots with nanometer precision is required to achieve highly sensitive and reproducible surface-enhanced Raman spectroscopy (SERS) analysis. In this article, molecular positioning at plasmonic nanogaps is reported using a high aspect ratio (HAR) plasmonic nanopillar array with a controlled surface energy. A large-area HAR plasmonic nanopillar array is generated using a nanolithography-free simple process involving Ar plasma treatment applied to a smooth polymer surface and the subsequent evaporation of metal onto the polymer nanopillars. The surface energy can be precisely controlled through the selective removal of an adsorbed self-assembled monolayer of low surface-energy molecules prepared on the plasmonic nanopillars. This process can be used to tune the surface energy and provide a superhydrophobic surface with a water contact angle of 165.8° on the one hand or a hydrophilic surface with a water contact angle of 40.0° on the other. The highly tunable surface wettability is employed to systematically investigate the effects of the surface energy on the capillary-force-induced clustering among the HAR plasmonic nanopillars as well as on molecular concentration at the collapsed nanogaps present at the tops of the clustered nanopillars. Molecular concentration at the electromagnetic hot spots is achieved using surface-enhanced Raman spectroscopy (SERS) substrates with controlled surface energies. The surface energies of the high aspect ratio plasmonic nanostructures are precisely controlled via the selective removal of low-surface energy chemicals that is chemisorbed onto the structures.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adfm.201703376

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.