Cysteamine-Modified Silver Nanoparticle Aggregates
for Quantitative SERS Sensing of Pentachlorophenol with a Portable
Raman Spectrometer
- Publication date
- Publisher
Abstract
Cysteamine-modified silver nanoparticle
aggregates has been fabricated
for pentachlorophenol (PCP) sensing by surface-enhanced Raman spectroscopy
(SERS) using a portable Raman spectrometer. The cysteamine monolayers
could preconcentrate PCP close to the substrate surface through the
electrostatic interaction, which makes the SERS detection of PCP possible.
Moreover, the Raman bands of cysteamine could be used as the internal
spectral reference in the quantitative analysis. Qualitative detection
of PCP was carried out by SERS without any sample pretreatment. Quantitative
analysis of PCP was further realized based on the prepared substrate,
as the log–log plot of normalized SERS intensity of PCP versus
its concentrations exhibits a good linear relationship. The SERS signals
collected on 20 randomly selected points show that the relative standard
deviation of the normalized Raman intensity is 5.8%, which indicates
the substrate had good uniformity. The PCP sensor also shows good
long-term stability in the analyte solution. The substrate was cyclic
immersed into PCP and methanol solution; after several cycles, the
sensor still had good adsorption to PCP, which revealed the sensor
has good reusability. Coupling with a portable Raman spectrometer,
the cysteamine-modified silver nanoparticle aggregates have the potential
to be used for in situ and routine SERS analysis of PCP in environmental
samples