Article pubs.acs.org/JPCC
Local Refractive Index Sensing Based on Edge Gold-Coated Silver Nanoprisms Erik Martinsson,† Mohammad Mehdi Shahjamali,‡ Karin Enander,† Freddy Boey,‡ Can Xue,‡ Daniel Aili,*,† and Bo Liedberg†,§ †
Division of Molecular Physics, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Sweden ‡ School of Materials Science and Engineering, Nanyang Technological University, Block N4.1, 50 Nanyang Avenue, Singapore 639798 § Centre for Biomimetic Sensor Science, Nanyang Technological University, 50 Nanyang Drive, Research Technoplaza, Sixth Storey, XFrontiers Block, Singapore 637553 S Supporting Information *
ABSTRACT: Bulk and surface refractive index sensitivity for localized surface plasmon resonance (LSPR) sensing based on edge gold-coated silver nanoprisms (GSNPs) and gold nanospheres was investigated and compared with conventional surface plasmon resonance (SPR) sensing based on propagating surface plasmons. The hybrid GSNPs benefit from an improved stability since the gold frame protecting the unstable silver facets located at the silver nanoprisms (SNPs) edges and tips prevents truncation or rounding of their sharp tips or edges, maintaining a high refractive index sensitivity even under harsh conditions. By using layer-by-layer deposition of polyelectrolytes and protein adsorption, we found that GSNPs exhibit 4-fold higher local refractive index sensitivity in close proximity (
