Date of Award

December 2020

Document Type


Degree Name

Doctor of Philosophy (PhD)


Food Technology

Committee Member

Paul Dawson

Committee Member

Timothy Hanks

Committee Member

Tzuen-Rong Tzeng

Committee Member

Julie Northcutt

Committee Member

William Pennington


Polydiacetylenes (PDAs) are conjugated polymers which consist of diacetylene monomers (DAs). DAs are colorless and can be polymerized under UV light at 254nm to form blue PDAs. Stimuli such as heat, chemicals, mechanic force and pH change will trigger color change of PDA from blue to red/pink. This chroma property makes PDA an ideal material for sensor development and therefore has received considerable attention in recent years. There has been several reports of generating PDA-based sensors for cations, chemicals, virus, microorganisms, and bacterial toxins detection. However, development of PDA-based sensors for food microbiology applications were limited. The objective of this study were thus to 1) investigate the sanitizers and surfactant effect on PDA-based sensors 2) develop a PDA-based biosensor for bacteria detection and verify the working mechanism 3) optimize and apply PDA-based biosensor for bacteria detection. 4) build and validate the statistical model for quantitative bacteria in samples. We started with generating liquid state PDA-based sensors and explored interaction between sanitizers/surfactant and PDA-based sensors. Subsequently, solid state PDA-based sensors were developed and detection mechanism for this method was verified with specifically designed experiments. Further, solid state PDA-based sensors were optimized and applied for bacteria detection with a statistical model built for quantitative bacteria in samples. This study provide a novel strategy of applying PDA-based biosensors for bacteria detection with quantitative measurement of bacteria and was supported by verified detection mechanism. Furthermore, this proposed method can be applied to quickly detect and quantify bacteria and may inspire other PDA-based biosensor design in the future.



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