New Surface-Enhanced Raman Spectroscopy Substrates via Self-Assembly of Silver Nanoparticles for Perchlorate Detection in Water

摘要

Perchlorate (ClO_(4~(-))) has recently emerged as a widespread contaminant in drinking water and groundwater supplies in the United States, and a need exists for rapid detection and monitoring of this contaminant. In this study, surface-enhanced Raman spectroscopy (SERS) was studied as a means of ClO_(4~(-)) detection, and new sol-gel-based SERS substrates were developed by self-assembly of silver colloidal nanoparticles with various functionalized silane reagents. These substrate materials were tailored to allow detection of ClO_(4~(-)) in water with improved sorptivity, stability, and sensitivity and with the ability to detect ClO_(4~(-)) at concentrations as low as 10~(-6) M (or 100 (mu)g/L) with good reproducibility. Similar techniques were used to fabricate capillary SERS flow cells by assembling functionalized silver nanoparticles capable of attracting ClO_(4~(-)) to the SERS surface or the internal wall of glass capillaries. These capillary flow cells could be readily configured to allow for in situ, nondestructive detection of ClO_(4~(-)) via fiber optics.