jp5b09570_si_001.pdf (4.63 MB)
Influence of the Particle Shape and Density of Self-Assembled Gold Nanoparticle Sensors on LSPR and SERS
journal contribution
posted on 2015-12-24, 00:00 authored by H. Yockell-Lelièvre, F. Lussier, J.-F. MassonA low-cost methodology to prepare
highly sensitive sensors is reported
with different nanoparticles for LSPR and SERS measurements. The LSPR
and SERS sensor was self-assembled as an array of polystyrene-capped
gold nanoparticles (Au NPs), produced by drop-coating a Au NP suspension
on a glass surface followed by plasma etching of the polystyrene.
The procedure was applied to different sizes and shapes of Au NPs,
primarily 60 nm gold nanospheres and 80 nm gold nanoraspberries, created
with precise control on the packing density of the array. The LSPR
sensitivity and figure of merit (FOM) for the arrays of gold nanoraspberries
were found to be almost 2-fold better than for the nanospheres and
had a shorter penetration depth, a consequence of their small-sized
surface asperities. The average measured SERS enhancement factor (EF)
for the raspberries was also higher than for spheres and control over
the EF was achieved using different packing densities which allowed
control of the interparticle coupling enhancing the SERS response.
The localized EF (hot spot) in dense arrays of nanoraspberries was
measured to be in the order of a typical EF required for single molecule
SERS, as demonstrated from the general agreement of experimental measurements
with simulations performed using Comsol Multiphysics. This simple
LSPR and SERS sensor could potentially serve as an effective platform
for the identification and quantification of various analytes.