Comparison of Fe2O3 and Fe2CoO4 core-shell plasmonic nanoparticles for aptamer mediated SERS assays

Haley Marks, Samuel Mabbott, Po-Jung Huang, George W. Jackson, Jun Kameoka, Duncan Graham, Gerard L. Coté

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

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Abstract

Conjugation of oligonucleotides or aptamers and their corresponding analytes onto plasmonic nanoparticles mediates the formation of nanoparticle assemblies: molecularly bound bundles of nanoparticles which cause a measurable change in the colloid's optical properties. Here, we present further optimization of a "SERS off" competitive binding assay utilizing plasmonic and magnetic nanoparticles for the detection of the toxin bisphenol A (BPA). The assay involves 1) a 'target' silver nanoparticle functionalized with a Raman reporter dye and PEGylated BPA-binding DNA aptamers, and 2) a version of the toxin BPA, bisphenol A diglycidyl ether (BADGE), PEGylated and immobilized onto a silver coated magnetic 'probe' nanoparticle. When mixed, these target and probe nanoparticles cluster into magnetic dimers and trimers and an enhancement in their SERS spectra is observed. Upon introduction of free BPA in its native form, target AgNPs are competitively freed; reversing the nanoparticle assembly and causing the SERS signal to "turn-off" and decrease in response to the competitive binding event. The assay particles were housed inside two types of optofluidic chips containing magnetically active nickel pads, in either a straight or spotted pattern, and both Fe2O3 and Fe2CoO4 were compared as magnetic cores for the silver coated probe nanoparticle. We found that the Ag@ Fe2O3 particles were, on average, more uniform in size and more stable than Ag@ Fe2CoO4, while the addition of cobalt significantly improved the collection time of particles within the magnetic chips. Using 3D Raman mapping, we found that the straight channel design with the Ag@ Fe2O3 particles provided the most uniform nanoparticle organization, while the spotted channel design with Ag@ Fe2CoO4 demonstrated a larger SERS enhancement, and thus a lower limit of detection.

Original languageEnglish
Title of host publicationColloidal Nanoparticles for Biomedical Applications XI
EditorsWolfgang J. Parak, Marek Osinski, Xing-Jie Liang
Number of pages8
Volume9722
DOIs
Publication statusPublished - 7 Mar 2016
EventColloidal Nanoparticles for Biomedical Applications XI - Moscone Center, San Francisco, United States
Duration: 13 Feb 201615 Feb 2016
http://spie.org/conferences-and-exhibitions/past-conferences-and-exhibitions/photonics-west-2016

Publication series

NameProceedings of SPIE
PublisherSPIE
Volume9722
ISSN (Print)1605-7422
ISSN (Electronic)2410-9045

Conference

ConferenceColloidal Nanoparticles for Biomedical Applications XI
CountryUnited States
CitySan Francisco
Period13/02/1615/02/16
Internet address

Keywords

  • aptamer
  • competitive binding assay
  • molecular diagnostics
  • plasmonic nanoparticles
  • surface enhanced Raman spectroscopy (SERS)
  • oligonucleotides
  • bisphenol A

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    Marks, H., Mabbott, S., Huang, P-J., Jackson, G. W., Kameoka, J., Graham, D., & Coté, G. L. (2016). Comparison of Fe2O3 and Fe2CoO4 core-shell plasmonic nanoparticles for aptamer mediated SERS assays. In W. J. Parak, M. Osinski, & X-J. Liang (Eds.), Colloidal Nanoparticles for Biomedical Applications XI (Vol. 9722). [97220N] (Proceedings of SPIE; Vol. 9722). https://doi.org/10.1117/12.2213735