Plastics and diagnostic assays with selective and sensitive macroscopic responses
Open Access
- Author:
- Lewis, Gregory Gerald
- Graduate Program:
- Chemistry
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- May 19, 2015
- Committee Members:
- Scott T Phillips, Dissertation Advisor/Co-Advisor
Philip C. Bevilacqua, Committee Member
Christine Dolan Keating, Committee Member
Enrique Daniel Gomez, Committee Member - Keywords:
- diagnostics
assay
point-of-care
analytical
polymers
depolymerization
additive manufacturing - Abstract:
- Depolymerizable polymers have been used in a variety of applications including as signal amplification reagents for sensors, responsive capsules, shape-changing plastics, and autonomous analyte-responsive pumps. This Thesis demonstrates the use of depolymerizable polymers for use as point-of-care (POC) sensors, as well as shape-changing materials. POC assays are used for detecting and quantifying analytes in environments that lack laboratory infrastructure. Quantitative POC assays are the most challenging to perform. They require measurements of both the duration of the assay and the output signal, and generally require both a handheld reader and a separate external timer. The ideal POC assay, as outlined by the World Health Organization, should be inexpensive, easy to use, and be equipment free. This Thesis seeks to address these challenges by creating quantitative POC assays that operate without using instruments or electronic readers. This Thesis describes the development of a proof-of-concept strategy that is based on controlling the flow of sample through paper in a way that depends both on the presence and concentration of a specific analyte. These assays use paper microfluidic devices and are able to quantify the levels of an analyte by measuring the time required for color to appear in a region on the device. The assays are based on selective changes in wetting properties of paper that has been modified with specific reagents that convert from hydrophobic to hydrophilic in response to a specific analyte. The application of depolymerizable polymers as shape-changing is also described in this Thesis. Depolymerizable polymers are used with an additive manufacturing, selective laser sintering (SLS), to form responsive 3-D objects. These objects can selectively respond to a variety of signals, resulting in macroscopic changes to the shape and properties of the plastic object.