Self-Assembled 3D Nanosplit Rings for Plasmon-Enhanced Optofluidic Sensing

Chunhui Dai, Zihao Lin, Kriti Agarwal, Carol Mikhael, Anupam Aich, Kalpna Gupta, Jeong-hyun Cho

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


Plasmonic sensors are commonly defined on two-dimensional (2D) surfaces with an enhanced electromagnetic field only near the surface, which requires precise positioning of the targeted molecules within hotspots. To address this challenge, we realize segmented nanocylinders that incorporate plasmonic (1-50 nm) gaps within three-dimensional (3D) nanostructures (nanocylinders) using electron irradiation triggered self-assembly. The 3D structures allow desired plasmonic patterns on their inner cylindrical walls forming the nanofluidic channels. The nanocylinders bridge nanoplasmonics and nanofluidics by achieving electromagnetic field enhancement and fluid confinement simultaneously. This hybrid system enables rapid diffusion of targeted species to the larger spatial hotspots in the 3D plasmonic structures, leading to enhanced interactions that contribute to a higher sensitivity. This concept has been demonstrated by characterizing an optical response of the 3D plasmonic nanostructures using surface-enhanced Raman spectroscopy (SERS), which shows enhancement over a 22 times higher intensity for hemoglobin fingerprints with nanocylinders compared to 2D nanostructures.

Original languageEnglish (US)
Pages (from-to)6697-6705
Number of pages9
JournalNano letters
Issue number9
StatePublished - Sep 9 2020

Bibliographical note

Funding Information:
This research was supported by the National Science Foundation under Grant CMMI-1454293. Portions of this work were conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nano Coordinated Infrastructure Network (NNCI) under Award Number ECCS-1542202. Parts of this work were carried out in the Characterization Facility, University of Minnesota, a member of the NSF-funded Materials Research Facilities Network ( ) via the MRSEC program. This work was supported partially by the National Science Foundation through the University of Minnesota MRSEC under Award Number DMR-2011401 and a grant from University of Minnesota Informatics Institute, which includes support from the University of Minnesota’s MnDRIVE Initiative. The authors acknowledge the Minnesota Supercomputing Institute (MSI) at the University of Minnesota for providing resources that contributed to the research results reported within this paper. C.D. acknowledges the support from Doctoral Dissertation Fellowship from University of Minnesota. K.G. acknowledges support from NIH RO1 HL147562. KG disclosures Honoraria: Tautona Group, Novartis and CSL Behring. Research Grants: Cyclerion, 1910 Genetics and Grifols. All others: Nothing to disclose. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Publisher Copyright:
© 2020 American Chemical Society.


  • 3D
  • nanofluidics
  • nanosplit rings
  • plasmonics
  • Raman
  • self-assembly

MRSEC Support

  • Partial

PubMed: MeSH publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Journal Article
  • Research Support, N.I.H., Extramural


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