ORCID
https://orcid.org/0009-0006-8714-1763
Date of Award
2025
Document Type
Dissertation
Degree Name
Biological Sciences (Ph.D.)
Department
Biological Sciences
First Advisor
Javier F Juárez
Second Advisor
Ales Vancura
Third Advisor
Dianella Howarth
Abstract
Biosensors are analytical devices that leverage biological modules for the detection of molecules of interest. As customizable tools designed to aid in a wide array of diagnostics, these instruments are rapidly advancing the field of synthetic biology. While varied in their construction and purpose, biosensors are ultimately concerned with converting a physicochemical stimulus into a detectable signal. Among the many existing variants, whole-cell biosensors (WCBs) stand out due to their versatility and engineering potential. WCBs are a type of biosensor in which a physiologically active cell sustains an array of biomolecular elements - receptors, transporters, regulators, etc. - capable of signal recognition, integration and actuation of an observable output. We focus here on the design of WCBs based on synthetic transcription factors, as they are adaptable sensing tools for the detection of small, soluble molecules of interest. This anthology describes the pipeline for the construction of a prokaryotic strain bearing a genetic circuit that integrates a custom-made transcription factor. To this end, we have utilized a live Escherichia coli cell in the construction of a library of synthetic transcription factors engineered to detect N-acetylneuraminic acid (Neu5Ac) - a salivary sialic acid and biomarker of oral cancer. Prominent among this library is a novel chimeric transcription factor known as Sphnx - MG1655 (pCKT-Sphnx, pHC_DYO-LacI-R) - which has been constructed and validated to detect exogenous Neu5Ac. This WCB and its cognates serve as proof-of-concept of a platform that can eventually be applied to clinical screening panels for a multitude of oral and systemic medical conditions whose biomarkers are present in saliva.
Recommended Citation
Verzino, Samuel J., "PROPELLING WHOLE-CELL BIOSENSOR CREATION BY LEVERAGING GENE FUSION TO ASSEMBLE SYNTHETIC FUNCTIONAL TRANSCRIPTION FACTORS FOR THE DETECTION OF BIOMARKERS" (2025). Theses and Dissertations. 996.
https://scholar.stjohns.edu/theses_dissertations/996