Ferric plasmonic nanoparticles, aptamers, and magnetofluidic chips: toward the development of diagnostic surface-enhanced Raman spectroscopy assays. Academic Article uri icon


  • Conjugation of aptamers and their corresponding analytes onto plasmonic nanoparticles mediates the formation of nanoparticle assemblies: molecularly bound nanoclusters that cause a measurable change in the colloids optical properties. The optimization of a surface-enhanced Raman spectroscopy (SERS) competitive binding assay utilizing plasmonic target and magnetic probe nanoparticles for the detection of the toxin bisphenol-A (BPA) is presented. These assay nanoclusters were housed inside three types of optofluidic chips patterned with magnetically activated nickel pads, in either a straight or array pattern. Both Fe 2 O 3 and Fe 2 CoO 4 were compared as potential magnetic cores for the silver-coated probe nanoparticles. We found that the Ag @ Fe 2 O 3 particles were, on average, more uniform in size and more stable than Ag @ Fe 2 CoO 4 , whereas the addition of cobalt significantly improved the collection time of particles. Using Raman mapping of the assay housed within the magnetofluidic chips, it was determined that a 1 5 array of 50 ?? ? m square nickel pads provided the most uniform SERS enhancement of the assay (coefficient of variation ? 25 % ) within the magnetofluidic chip. Additionally, the packaged assay demonstrated the desired response to BPA, verifying the technologys potential to translate magnetic nanoparticle assays into a user-free optical analysis.

published proceedings

  • J Biomed Opt

author list (cited authors)

  • Marks, H., Huang, P., Mabbott, S., Graham, D., Kameoka, J., & Cot, G.

citation count

  • 5

complete list of authors

  • Marks, Haley||Huang, Po-Jung||Mabbott, Samuel||Graham, Duncan||Kameoka, Jun||Coté, Gerard

publication date

  • December 2016