Development of Solution Blow Spun Nanofibers as Electrical and Whole Cell Biosensing Interfaces

Infectious pathogens place a huge burden on the US economy with more than $120 billion spent annually for direct and indirect costs for the treatment of infectious diseases. Rapid detection schemes continue to evolve in order to meet the demand of early diagnosis. In chronic wound infections, bacterial load is capable of impeding the healing process. Additionally, bacterial virulence production works coherently with bacterial load to produce toxins and molecules that prolongs the healing cycle. This work examines the use of nonwoven polymeric conductive and non-conductive nanofiber mats as synthetic biosensor scaffolds, drug delivery and biosensor interface constructs. A custom-made nanofiber platform was built to produce solution blow spun nanofibers of various polymer loading. Antimicrobial nanofiber mats were made with the use of an in-situ silver chemical reduction method. Ceria nanoparticles were incorporated to provide an additional antioxidative property. Conductivity properties were examined by using silver and multi-walled carbon nanotubes (MWCNT) as a filler material. SBS parameters were adjusted to analyze electrical conductivity properties. Nanofiber mats were used to detect bacteria concentrations in vitro. Protein adhesion to conductive nanofibers was studied using fluorescent antibodies and BCA assay. Anti-rabbit and streptavidin Alexa Flour 594 was used to examine the adsorption properties of SBS nanofiber mats. Enhancements were made to further improve interface design for specificity. SBS nanofiber electrodes were fabricated to serve as scaffold and detection site for spike protein detection. Bacteria virulence production was examined by the detection of pyocyanin and quorum sensing molecules. The opportunistic pathogen, Pseudomonas aeruginosa is a nosocomial iii pathogen found in immunocompromised patients with such as those with chronic wounds and cystic fibrosis. Pyocyanin is one of four quorum sensing molecules that the pathogen produces which can be detected electrochemically due to its inherent redox-active activity. SBS has been used to develop a sensing scheme to detect pyocyanin. This work also examines the use of a synthetic biosensor with a LasR based system capable of detecting homoserine lactone produced by P. aeruginosa and other common gram-negative pathogens. Genetic modifications were made to biosensor in order to replace a green, fluorescent reporter with a chromoprotein based reporter system for visual readout. Additionally, work related to community service and outreach regarding the encouragement of middle school students to pursue Science, Technology, Engineering and Math (STEM) was conducted. Results from outreach program showed an increase in the STEM interest among a group of middle school students. There was a general trend with STEM career knowledge, STEM self-efficacy and the level of interest in STEM careers and activities. Military research was also done with the United States Army Medical Research Institute of Infectious Diseases (USAMRIID) to develop several assays for the detection of several highly infectious viruses and bacteria. Due to confidentiality, the work cannot be published in this manuscript