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Overcoming evanescent field decay using 3D-tapered nanocavities for on-chip targeted molecular analysis

Kumar, Shailabh and Park, Haeri and Cho, Hyunjun and Siddique, Radwanul H. and Narasimhan, Vinayak and Yang, Daejong and Choo, Hyuck (2020) Overcoming evanescent field decay using 3D-tapered nanocavities for on-chip targeted molecular analysis. Nature Communications, 11 . Art. No. 2930. ISSN 2041-1723. PMCID PMC7287113.

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Enhancement of optical emission on plasmonic nanostructures is intrinsically limited by the distance between the emitter and nanostructure surface, owing to a tightly-confined and exponentially-decaying electromagnetic field. This fundamental limitation prevents efficient application of plasmonic fluorescence enhancement for diversely-sized molecular assemblies. We demonstrate a three-dimensionally-tapered gap plasmon nanocavity that overcomes this fundamental limitation through near-homogeneous yet powerful volumetric confinement of electromagnetic field inside an open-access nanotip. The 3D-tapered device provides fluorescence enhancement factors close to 2200 uniformly for various molecular assemblies ranging from few angstroms to 20 nanometers in size. Furthermore, our nanostructure allows detection of low concentration (10 pM) biomarkers as well as specific capture of single antibody molecules at the nanocavity tip for high resolution molecular binding analysis. Overcoming molecule position-derived large variations in plasmonic enhancement can propel widespread application of this technique for sensitive detection and analysis of complex molecular assemblies at or near single molecule resolution.

Item Type:Article
Related URLs:
URLURL TypeDescription CentralArticle
Kumar, Shailabh0000-0001-5383-3282
Siddique, Radwanul H.0000-0001-7494-5857
Narasimhan, Vinayak0000-0003-4165-402X
Yang, Daejong0000-0002-8774-5843
Choo, Hyuck0000-0002-8903-7939
Additional Information:© The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit Received 18 June 2019; Accepted 27 May 2020; Published 10 June 2020. Device fabrication was performed at the Kavli Nanofabrication Center at California Institute of Technology. Fluorescence imaging was performed at the Beckman Imaging center at California Institute of Technology. Funding for this research was provided by HMRI Investigator award and Samsung Global Research Outreach (GRO) program. Data availability: The data that support the findings of this study are available from the corresponding author upon reasonable request. Author Contributions: S.K., H.P., and H.C. conceived the study. S.K. performed the device fabrication and the molecular fluorescence experiments. H.P. performed the theoretical device design optimization and numerical simulations. HJ.C. and D.Y. helped establish device fabrication protocol. R.H.S. helped with numerical simulations and device optimization. V.N. assisted with data visualization and validation. S.K., H.P., and H.C. wrote the paper. The authors declare no competing interests.
Group:Heritage Medical Research Institute, Kavli Nanoscience Institute
Funding AgencyGrant Number
Heritage Medical Research InstituteUNSPECIFIED
SAMSUNG Global Research OutreachUNSPECIFIED
Subject Keywords:Biosensors; Nanocavities; Nanophotonics and plasmonics
PubMed Central ID:PMC7287113
Record Number:CaltechAUTHORS:20200611-124557130
Persistent URL:
Official Citation:Kumar, S., Park, H., Cho, H. et al. Overcoming evanescent field decay using 3D-tapered nanocavities for on-chip targeted molecular analysis. Nat Commun 11, 2930 (2020).
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:103856
Deposited By: Tony Diaz
Deposited On:11 Jun 2020 20:15
Last Modified:06 Jul 2020 20:51

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