LSPR Nano-Immunosensor for Simple and Sensitive Water Monitoring

There is an ever-present need to know what is in our nation’s water in order to protect our people and the environment. The issue of ensuring the safety of drinking water has become more critical in light of homeland security concerns. Water systems must guard against contamination from typical wastes, and be able to monitor for bacteria, toxins, spores, and viruses that can be introduced into drinking water supplies at numerous points in the source and distribution networks. In view of the increasing threat, it is highly desirable to have water monitoring results available in real-time, or near real-time, for purposes of process control, or rapid intervention, in the case of a serious problem or threat. Laboratory tests, such as immunoassays, exist for toxins and microorganisms, but it is not currently possible to monitor for their presence on-line, in near real-time, because of the complexity of the tests. Intelligent Optical Systems intends to address the current limitations of available water monitoring technologies by applying emerging optical detection and nanotechnologies to develop on-line water monitoring instrumentation that will be capable of detecting a wide range of organic pollutants, toxins, and microorganisms in a multiplexed fashion. One innovative aspect of the proposed detection method is that immunoassays can be performed in a simplified manner where no additional reagents or labeled molecules are required. The assays can be performed using inexpensive, disposable flow cell cartridges that can be chosen for the assays of interest. Thus, it will be possible to obtain near real-time results in a portable, field use format. The objectives of the proposed study are to demonstrate the use of this innovative optical assay for both a toxin and a microorganism present in a flowing stream of water. As part of the proposed studies, a disposable flow cell will be designed and fabricated to implement the innovative optical immunoassays. These cells will be used to demonstrate the assay of a toxin, microcystin, and E. coli bacterial cells. The success of the proposed work will result in the capability to conduct water monitoring for organic chemicals, toxins, and microorganisms in near real-time using economical instrumentation that can be operated in an unattended fashion. The anticipated commercial applications for this water monitoring system include: monitoring surface water, monitoring source water at drinking water processing facilities, monitoring water in air conditioning systems, and monitoring drinking water in distribution systems.