Portable Optical Imager for Multiplexed Foodborne Pathogen Detection

Portable Optical Imager for Multiplexed Foodborne Pathogen Detection Project Summary Food contamination caused by pathogens is a significant public health concern for consumers worldwide. Critical aspects of limiting foodborne disease outbreaks and epidemic involve early detection and rapid diagnostics of foodborne pathogens which require sensitive, multiplexed devices that enable point-of-care (POC) diagnostics. New generations of rapid (detection in minutes to hours), portable, multiplexed and sensitive biosensors can significantly aid in delivery of a safer food supply. Nanohmics proposes to develop a low-cost portable optical imager that is capable of fast (lt 30 minutes), sensitive (tens to hundreds of bacteria or viruses), and multiplexed testing of up to tens of foodborne pathogens from fresh produce swab fluids or rinsates and comparable food surface samples. Specifically, the proposed research will integrate low-cost large-area pixelated nanohole array (NHA) biosensing chips and economical optical and electronical components in to a compact, highly portable, battery-operated and rugged biosensor device. While NHA plasmonic biosensors already exist as bench-level laboratory experimental set ups, the technology has not been innovated to make it portable and multiplexed for field use to test numerous imported or domestic foods onsite where the FDA and USDA are overwhelmed with samples. Compared to conventional reflection-type plasmonic biosensors employing a prism, NHAs support collinear excitation and collection configuration. This not only significantly simplifies alignment and but also enables small footprint and highly multiplexed biosensing. Nanohmics will microspot NHA-based pixel arrays with different bioreceptors where the type of target is encoded in the position of the corresponding spot pixels. The team will engineer and construct an optical imager using a wide-beam red laser module, a miniaturized imaging lens, and a CMOS detector, and integrate the bioreceptor-pixelated NHA biosensing chips with the optical imager for field-portable rapid multiplexed testing of infectious pathogens. The overall integrated device is envisioned to be compact (~ 5 × 5 × 10 cm3), light (~ 100 g), and low-cost (~ $ 400 including fabrication and parts). Nanohmics aims at rapid (lt 30 minutes) and sensitive detection with limit of detection in the tens to low hundreds of bacteria and viruses per mL.