The Development of a Portable Arsenic Detector Based on Surface-Enhanced Raman Spectroscopy for Rapid on-Site Testing of Groundwater

摘要

The combination of high toxicity and widespread occurrence has created a pressing need for effective monitoring of arsenic in groundwater. In this paper, we discuss the development and performance of a field deployable monitoring tool based on surface enhanced Raman spectroscopy (SERS) that can be used for rapid on-site detection and quantification of arsenic in groundwater. More specifically, we discuss (1) the fabrication of close-packed metal nanoparticle film in large scale as SERS substrate via a two-phase interfacial self-assembly process; (2) the fabrication of a SERS sampling module that can house the SERS substrate and also attaches to a fiberoptic Raman probe; and (3) the detection of ppb level arsenic using the assembled portable SERS system. Because of the low cost associated with the SERS sensor materials and fabrications, they can be manufactured as disposable products so that any possible contaminants from analytes (i.e., arsenic) deposited from previous measurements can be avoided.