The advent of lasers created a revolution in spectroscopic techniques starting in the 1970s. Raman analysis is a fine example, as intense laser light is required to generate detectable signals. Raman has exciting prospects for environmental applications becasuse water does not prove a significant background against chemical analysis, unlike infrared or some visible regimes. The refinement of surface enhanced Raman spectroscopy (SERS) has further pushed the utility of this technique into myriad systems. In this Feature, Halvorson and Vikesland overview the theory and methods, and illustrate environmental applications from contaminant to pathogen detection.
Despite extensive efforts to protect public health, disease outbreaks still occur when toxic chemicals and microbial threats evade detection. Peanut butter and produce tainted with Escherichia coli 0157:H7, drinking water in Milwaukee, WI and Walkerton, ON (Canada) polluted by Cryptosporidium, surface waters contaminated by cyanotoxins, and mail laced with anthrax spores each represent an outbreak that may have been prevented with faster and more readily available pathogen or chemical detection methods. Although numerous techniques for contaminant detection in a variety of matrices exist, monitoring each analyte class generally requires specific instrumentation. Today, however, there is growing excitement about the potential use of surface-enhanced Raman spectroscopy (SERS) for simultaneous multiplex detection of infectious and noninfectious contaminants in a range of environmental milieu. As currently envisioned, SERS is a platform for simple, fast, inexpensive, reliable, and robust methods to screen single or multiple contaminant classes simultaneously (1-4). Thousands of SERS publications document significant progress in achieving such a vision; however, as outlined herein several surmountable obstacles must be overcome to achieve these goals.
