A Nanocrystal Biosensor Array for Simultaneous Detection of Multiple Waterborne Pathogens

The goal of this research project is to develop a new generation of sensitive, rapid, portable, robust, and inexpensive biosensors for the simultaneous detection of multiple waterborne pathogens in water products and the environment. Specifically, Nanomaterials & Nanofabrication Laboratories will develop new biomarkers by conjugating the various color nanocrystals onto the monoclonal antibodies and a new flow cell to specifically capture and concentrate the waterborne pathogens by immobilizing the monoclonal antibodies onto the porous membrane surface. The feasibility of this technology will be demonstrated by detecting protein A with the biosensor setup and using a photoluminescence detector to measure the photoluminescence emitted from the nanocrystals on the immunocomplexes. The nanocrystals as biomarkers make the biosensors capable of simultaneously detecting multiple waterborne pathogens in the same setup with a laser source because of their broad excitation spectra, narrow and symmetric emission spectra, and high resistance to photobleaching. The high density of the immobilized antibodies on the porous membrane surface will quantitatively capture the waterborne pathogens so that the sensitivity of the biosensor will be greatly enhanced and the detection limit will be lowered to one cell per one of the pathogens. The monoclonal antibodies used will diminish the nonspecific binding and the positive false signal. The nanocrystal biosensor array introduced during this project will address a critical need in the drinking water market. A reliable, sensitive, in situ device for monitoring multiple waterborne pathogens is needed in every drinking water processing facility in the United States. The nanocrystal biosensor array also can detect multiple pathogens simultaneously in food products for the food production and sales industries, and meet the new U.S. Department of Agriculture regulations and enhance Hazard Analysis and Critical Control Points programs for food safety. These industries could benefit economically from this novel technology in terms of preventing product recalls and international embargos resulting from microbially contaminated products. This technology could benefit society by saving lives, reducing disease, and reducing medical costs. Furthermore, the technology possesses a strong potential to be extended to the detection of biohazards in the environment caused by biological warfare and other sources. Although this proposal focuses on civilian purposes, the technology also may be used for U.S. military applications.