In-situ partial sintering of gold-nanoparticle sheets for SERS applications.
A new, versatile substrate design for surface-enhanced Raman spectroscopy (SERS) is introduced that provides better illumination and collection efficiency than other solid substrates. It uses sheets of 5 nm diameter gold nanoparticles that are draped by drying-mediated self-assembly onto 100 nm thick silicon nitride membranes. During laser illumination, partial in-situ sintering of the nanoparticles into larger structures with tiny gaps (≈2 nm) greatly increases the SERS enhancement factor. The detection of 1 pM of p-mercaptoaniline and 1 fg of 2,4-dinitrotoluene is demonstrated. The use of self-assembled nanoparticle sheets furthermore makes it possible to perform SERS detection in situ on top of a probe solution droplet.
James Franck Institute, The University of Chicago, Chicago, IL 60637, USA.
Jinbo
J
He
Xiao-Min
XM
Lin
Ralu
R
Divan
Heinrich M
HM
Jaeger
D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D055620:Optical Phenomena; D017655:Silicon Compounds / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*
D017655:Silicon Compounds; D006046:Gold; C032734:silicon nitride