20 December 2016 Ferric plasmonic nanoparticles, aptamers, and magnetofluidic chips: toward the development of diagnostic surface-enhanced Raman spectroscopy assays
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Abstract
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 colloid’s 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    μ 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 technology’s potential to translate magnetic nanoparticle assays into a user-free optical analys
© 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)
Haley Marks, Po-Jung Huang, Samuel Mabbott, Duncan Graham, Jun Kameoka, Gerard Coté, "Ferric plasmonic nanoparticles, aptamers, and magnetofluidic chips: toward the development of diagnostic surface-enhanced Raman spectroscopy assays," Journal of Biomedical Optics 21(12), 127005 (20 December 2016). https://doi.org/10.1117/1.JBO.21.12.127005 . Submission: Received: 20 August 2016; Accepted: 17 November 2016
Received: 20 August 2016; Accepted: 17 November 2016; Published: 20 December 2016
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