College - Author 1

College of Engineering

Department - Author 1

Biomedical Engineering Department

Degree Name - Author 1

BS in Biomedical Engineering

College - Author 2

College of Engineering

Department - Author 2

Biomedical Engineering Department

Degree - Author 2

BS in Biomedical Engineering

College - Author 3

College of Engineering

Department - Author 3

Biomedical Engineering Department

Degree - Author 3

BS in Biomedical Engineering

Date

5-2020

Primary Advisor

Ben Hawkins, College of Engineering, Biomedical Engineering Department

Additional Advisors

Michael Whitt, College of Engineering, Biomedical Engineering Department

Abstract/Summary

This project aimed to develop a process to create a hydrophobic coating with capture antibodies attached. This process was developed in an attempt to create a digital microfluidic platform upon which an enzyme-linked immunosorbent assay (ELISA) could be run, indicated for clinicians and educators in low-resource settings. Four requirements dictated the course of the design process: 1) the contact angle with water of the hydrophobic layer must be greater than 90º, 2) the colorimetric response of a positive ELISA result on our platform must be at least 85% of that run on polystyrene with the same result, 3) the platform with pre-immobilized antibodies must last at least two weeks on the shelf, and 4) the platform must confer a cost of at most $10 per test.

The design process began with brainstorming ideas for low-cost hydrophobic materials for use in the hydrophobic layer. We began testing with Parafilm, as it is inexpensive and easily accessible. We were fortunate to provide Proof of Concept with Parafilm early on in the process, finding that Parafilm has an average contact angle of 103º with water. We went on to prove that there is no significant difference in contact angle between either side of the Parafilm strip, a test requested by our sponsor to increase ease of use.

Following the water contact angle tests, we planned to perform contact angle tests with ELISA reagents (Triton-X and DPBS) to confirm that the ELISA could be run on Parafilm with little interference. We were optimistic about the results of this test and planned to move forward with studies into the mechanism by which we would immobilize antibodies atop the Parafilm next. Unfortunately, the Coronavirus pandemic made it so we did not have access to the facilities we needed to perform these tests. As such, we pivoted and prepared to provide a construction package with detailed future test plans as our deliverable instead. The construction package outlined in this document provides the next group to pick up the OpenDrop ELISA project with protocols for the ELISA reagent contact angle test and antibody immobilization studies. It is important that they are run in that order, so as to maintain Proof of Concept for the Parafilm-based platform.

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