Water Security Monitoring using Surface-Enhanced Raman Spectroscopy

Clean drinking water is a critical component of the United States infrastructure and is therefore a potential target for terrorists. In addition to physical attacks to the water network including dams, pumping stations and pipelines, there must be vigilance to prevent the water itself from being fouled through the addition of toxic/hazardous chemicals. It is virtually impossible to protect every river, stream, or lake that contributes to the nation’s drinking water supply. Therefore, rapid detection of a chemical/biological attack followed by rapid remediation is paramount. Many toxins are deadly at very low dosages (low parts per billion [ppb] or less for chemical, 1-100 cts/mL for biologic), requiring sensitive and precise measurements. Immediate on-site identification and action precludes the transport of samples to a laboratory setting. This program will demonstrate the capabilities of a hand-held sensor that potentially could be used in-line. This sensor is based on the technique of Surface-Enhanced Raman Spectroscopy (SERS); the ability of SERS to detect chemical warfare agents was demonstrated at EIC Laboratories during the Joint Services Agent Water Monitor program. In addition, bacteria, toxins, pesticides, cyanotoxins and explosives have been effectively detected in water. The ability to mass produce reproducible sensors has recently enabled increased precision and sensitivity. In the Phase I program, the ability to precisely detect an agent degradation product, seven pesticides, and a toxin will be tested in water samples in the presence of various natural interferences. During the Phase II program, the SERS database will be extended to include additional pesticides, toxic industrial chemicals, toxins and bacteria, and a field portable unit, incorporating the SERS library, will be produced and tested at an U.S. Environmental Protection Agency (EPA) defined site.