1 research outputs found
Fabrication of an Optoplasmonic Raft with Improved SERS Performance Detecting Methamphetamine through Bubble Enrichment
In
this work, a novel raft-like structure that combines noble metal
nanoparticles (NPs) with an interconnected layer of hemispherical
dielectric shell was fabricated and characterized. It was discovered
that this hybrid material can enhance the optoplasmonic interaction
between plasmonic and dielectric components, thereby improving the
sensing performance in surface-enhanced Raman spectroscopy (SERS).
Varied geometric parameters of the fabricated optoplasmonic raft,
including the inner diameter and thickness of the dielectric shell,
were attempted and analyzed through numerical simulation and experimental
SERS measurements. With particular size, thickness, and incident orientation,
the silica shell focuses the incident optical flow into the deposited
silver NPs, undergoing similar near-field focusing behavior in comparison
with other optoplasmonic entities. This optoplasmonic raft floating
on the water surface is able to harvest the target molecules effectively
through bubble enrichment, which rapidly captures and concentrates
analytes from the aqueous phase. With a limited sampling time, the
sensing performance of the developed optoplasmonic raft is improved
by applying the optimized parameters involved in bubble enrichment.
The substrates and corresponding enrichment method were implemented
in the detection of methamphetamine (METH), achieving a limit of detection
(LOD) down to 0.035 nM. As for practical onsite detection, the developed
substrate and bubbling strategy were applied in an assembled set,
employing a portable Raman spectrometer and an air pump. This set
is able to detect METH dissolved in regular commercial beer, which
is quite competent in the investigation of drug abuse