Induction of Hypohalous Acid Formation by Photoinducible Carbon Nitride Complexes

Author

Ashley Marie Williams, Boise State UniversityFollow

Publication Date

5-2025

Date of Final Oral Examination (Defense)

3-7-2025

Type of Culminating Activity

Thesis

Degree Title

Master of Science in Chemistry

Department

Chemistry and Biochemistry

Supervisory Committee Chair

Kenneth A. Cornell, Ph.D.

Supervisory Committee Member

John Thurston, Ph.D.

Supervisory Committee Member

Javier Ochoa-Reparaz, Ph.D.

Abstract

Due to the continuous rise in antibiotic resistance, there is an urgent need to develop novel antimicrobial compounds and therapeutic approaches to combat biofilm-associated infections. The rise in antibiotic resistance has contributed significantly to increased global healthcare costs. Graphitic carbon nitrides are photoinducible, metal-free semiconductors that release free electrons when irradiated with 405 nm light. These free electrons interact with atmospheric oxygen to produce reactive oxygen species (ROS) that can further interact with halide ions (Cl^-, Br^-, I^-) to form hypohalous acids, such as hypochlorous acid (bleach) that have antimicrobial activity. In this thesis research, a specific carbon nitride formulation that incorporated a nonasodium nonatungstobismuthate hexadecahydrate (Na₉[α-β-BiW₉O₃₃] · 16H₂O) catalyst, was evaluated for enhanced ROS generation and subsequent hypohalous acid production. Compared to the carbon nitride complex alone, incorporation of the (Na₉[α-β-BiW₉O₃₃] · 16H₂O) catalyst led to increased antimicrobial activity against Gram-negative Pseudomonas aeruginosa (PAO1) biofilms. The mechanisms of antimicrobial action were evaluated by analyzing the production of ROS and reactive halogen species (RHS) and the halogenation of quorum-sensing molecules using high-performance liquid chromatography coupled mass spectrometry (HPLC-MS). The ultimate goal of examining these carbon nitride complexes is to develop novel treatments for chronic wounds, biofilm infections, and other topical applications in the healthcare industry.

DOI

10.18122/td.2386.boisestate

Recommended Citation

Williams, Ashley Marie, "Induction of Hypohalous Acid Formation by Photoinducible Carbon Nitride Complexes" (2025). Boise State University Theses and Dissertations. 2386.
10.18122/td.2386.boisestate