Recipient Organization
LINCOLN UNIVERSITY
820 CHESTNUT ST
JEFFERSON CITY,MO 651023537
Performing Department
Agriculture
Non Technical Summary
The project will develop a transformative impedance-based MEMS biosensor for simultaneous detection of E. coli O157:H7 and Salmonella at a concentration toward 1 cell/325 gr within 4-7 hours. This project will focus on meat products, such as ground meat and cube steaks.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
The proposed project will develop a transformative impedance-based MEMS biosensor for simultaneous detection of E. coli O157:H7 and Salmonella at a concentration toward 1 cell/325 gr within 4-7 hours. This project will focus on meat products, such as ground meat and cube steaks. We will pursue the following objectives:Investigate, design, and fabricate innovative impedance-based MEMS biosensors for the simultaneous detection of E. coli O157:H7 and Salmonella within 4-7 hours.Optimize the on-chip enrichment region to culture the maximum number of cells and optimize the antibody immobilization and binding process on the interdigitated electrode arrays to provide the maximum coating within the shortest time.Test and validate the fabricated biosensors, and determine the minimally required detection time for using cube steaks and ground meat products.
Project Methods
Task a: Design an on-chip enrichment region using multiple trapping sites to trap the pathogens. The on-chip enrichment region consists of multiple trapping sites, with a total area of 2×2 mm2. Each site consists of four metallic micro-posts with elliptical shapes (i.e., diameter of 20 µm; center-to-center spacing of 40 µm).Task b: Design two sets of focusing electrodes to concentrate the food sample.The focusing region (length 5 mm) is designed to significantly improve the focusing capability of the device by eliminating over 90% of the testing media volume. This results in a concentrated sample and significantly improves the chances of detecting pathogens.Task c: Design vertical electrodes with an elliptical shape that employ p-DEP to trap the pathogens, e.g., E. coli, on top of the detection electrodes. The cell trapping regions consist of a half-elliptical shape surrounding the detection IDE arrays. The trapping electrodes are used to generate a high E-field gradient to force the E. coli cells to move toward the region with a high E-field gradient and trap them on top of the detection IDE arrays.Task d: Design two sets of interdigitated electrode (IDE) arrays to achieve high sensitivity and selective detection of single or multiple foodborne pathogens.The detection region consists of a unique design: four sets of IDE arrays, each with 10-20 finger pairs. In addition, each of the two sets is surrounded by one tapping electrode pair.Task.e: Establish the microfabrication processes and fabricate the proposed impedance-based MEMS biosensors using surface micromachining technology.The fabricated biosensors form the backbone of the proposed device. However, further optimization is required to produce reliable devices due to the use an innovative on-chip enrichment region and two sets of focusing electrodes, with a wide range of widths and lengths (e.g., from a few µm to mm), a trapping electrode with vertical walls, and multi-interdigitated electrode arrays that vary from those previously fabricated. In this case, the finger width and spacing between the fingers will be much smaller than what we had previously fabricated (a channel with a width between 33-100 µm), and the height will be increased to 30-100 µm to accommodate a larger volume of bacterial sample.