Homogeneous Plasmonic Assays for Instantaneous Microbial Detection

PI: Abbas, Abdennour <br/>Proposal Number: 1605191<br/><br/>A new approach for a rapid identification and quantification of microbial content and type in food and environmental samples will be investigated. If successful, the results could address current need in food safety and food spoilage detection.<br/><br/>A new approach for rapid identification and quantification of the microbial content and type in food and environmental samples, will be investigated. Rapid screening (less than 2 hours) for the presence or absence of yeasts, molds, gram-negative bacteria, gram-positive bacteria and other phylogenetic microbial classes regardless of the strain or species will be developed. Current rapid methods rely on incubation followed by polymerase chain reaction (PCR) for identification. The proposed homogeneous phylogenetic-plasmonic assays are based on the combination of plasmonic and colorimetry mechanisms (generation of color by the aggregation of metal nanoparticles), and the identification and targeting of specific phylogenetic entities on the microbial surface, which are specific to a certain class of microorganisms, and can be activated to interact with plasmonic nanoparticles. Such an interaction results in a rapid formation of a nanoparticle monolayer surrounding the microorganism, leading to rapid color change of the sample from red to dark-blue, visible to the naked eye. As a result, the proposed assay technology is expected to reduce cost and time needed for analysis and decision making would become feasible in less than two hours. Beyond the applied aspects of the project, the proposed research will explore microbial surface entities, particularly disulfide bridge-containing proteins, and shed light on their importance, distribution and role in molecular recognition reactions and stability of microbial cells. The main direct impact of this research is to enhance the capabilities of food and environmental diagnostic laboratories by enabling rapid microbial screening in food plants and environmental sites, allowing timely implementation of a preventive or curative response. The project proposes to build collaboration with industrial partners, which will help fill the gap between academic research and the development of commercial products that benefit society. The proposed research program will introduce graduate, undergraduate students, and post-docs to transdisciplinary research and educate them on how to solve problems by applying different fields of science and engineering, such as nanotechnology, chemistry, biotechnology and food engineering. The results of this research will be broadly disseminated through conferences, peer-reviewed publications, potential patents and news articles to inform the general public.