Project Grant 2213222

LEAPS-MPS: METAL-FREE CARBONS AS EFFICIENT ANTIBACTERIAL MATERIALS -LEAPS-MPS: METAL-FREE HETEROATOM-DOPED CARBONS AS ANTIBACTERIAL MATERIALS NON-TECHNICAL SUMMARY BACTERIAL CONTAMINATION IN WASTEWATER SYSTEMS PRESENTS A SIGNIFICANT THREAT TO PUBLIC HEALTH. EFFECTIVE WATER TREATMENT IS CRUCIAL DUE TO SOCIETY'S RAPID INDUSTRIALIZATION AND URBANIZATION, AND DRINKABLE WATER SHOULD BE FECAL AND TOTAL COLIFORMS FREE. THIS PROJECT AIMS TO INVESTIGATE THE ANTIBACTERIAL ACTIVITY OF POROUS CARBON MATERIALS THAT ARE DOPED WITH SULFUR OR/AND NITROGEN-CONTAINING SPECIES. IT WILL OPEN A NEW PERSPECTIVE ON THESE METAL-FREE MATERIALS IN ANTIBACTERIAL STUDIES. BY LINKING THE PROPERTIES OF THE CARBON TO THEIR PERFORMANCE IN BACTERIAL INHIBITION, THE MOST EFFECTIVE FEATURES OF THE CARBONS WILL BE IDENTIFIED. WHY THESE SPECIES ARE EFFECTIVE WILL BE EXPLORED TOO. THIS PROJECT WILL LAY A SOLID FOUNDATION FOR THE LONG-TERM MATERIAL DEVELOPMENT OF POTENT METAL-FREE ANTIBACTERIAL MATERIALS. METAL-FREE MATERIALS OFFER THE ADVANTAGE OF REDUCED COST FOR THE WATER TREATMENT PROCESS. BESIDES, THEY CAN BE POTENTIALLY APPLIED TO THE EXISTING FILTRATION SYSTEMS IF THEY POSSESS EFFECTIVE ANTIBACTERIAL EFFECTS. THE PROJECT WILL PROVIDE AN EARLY-CAREER FACULTY TO DEVELOP A RESEARCH LAB AND LAUNCH RESEARCH PROGRAMS. IT WILL ALSO HELP THE UNDERGRADUATE STUDENTS ACHIEVE THEIR EDUCATIONAL AND CAREER GOALS, ESPECIALLY THOSE FROM UNDERREPRESENTED MINORITY GROUPS. TECHNICAL SUMMARY THIS INTERDISCIPLINARY PROJECT IS TO INVESTIGATE THE ANTIBACTERIAL ACTIVITY OF HETEROATOM-DOPED POROUS CARBON MATERIALS SYSTEMATICALLY. THE RELATIONSHIP BETWEEN THE PROPERTIES (SURFACE CHEMISTRY AND TEXTURE) OF CARBONS AND THEIR PERFORMANCE IN BACTERIAL INHIBITION WILL BE MAINLY STUDIED. BY USING IN-SITU DOPING OR POST-TREATMENT METHODS, A SERIES OF DOPED-POROUS CARBONS WILL BE PREPARED AND FUNCTIONALIZED OF DOPING SULFUR OR/AND NITROGEN GROUPS. ESCHERICHIA COLI (E. COLI) AND STAPHYLOCOCCUS AUREUS (S. AUREUS) ARE SPECIFICALLY SELECTED FOR TESTING SINCE THEY ARE THE MOST PREVALENT SPECIES OF GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA, RESPECTIVELY. THE BACTERIOSTASIS RATE OF THE CARBONS WILL BE CALCULATED. A TYPICAL INACTIVATION PATHWAY FOR BACTERIA ON A CARBON-BASED MATERIAL IS OXIDATION STRESS. THE MECHANISM OF THE ANTIBACTERIAL PROCESS WILL BE EXPLORED BY IDENTIFYING THE TYPES OF REACTIVE OXYGEN SPECIES (ROS) GENERATED FROM THE CARBONS. THE MATERIALS WILL BE INTENSIVELY CHARACTERIZED BY X-RAY PHOTOELECTRON SPECTROSCOPY ANALYSIS, THERMAL ANALYSIS, POROSITY ANALYSIS, POTENTIOMETRIC TITRATION, AND ELECTRON MICROSCOPY IMAGING. THE PROJECT WILL FOCUS ON IDENTIFYING DOPANT SPECIES THAT ARE EFFICIENT IN BACTERIAL INHIBITION, THUS ESTABLISHING CARBON MATERIALS AS EFFECTIVE ANTIBACTERIAL MATERIALS. FOR THE PHOTOACTIVE CARBONS, THEIR ANTIBACTERIAL ACTIVITY AND MECHANISM WILL ALSO BE EVALUATED UNDER VISIBLE LIGHT RADIATION. THIS AWARD REFLECTS NSF'S STATUTORY MISSION AND HAS BEEN DEEMED WORTHY OF SUPPORT THROUGH EVALUATION USING THE FOUNDATION'S INTELLECTUAL MERIT AND BROADER IMPACTS REVIEW CRITERIA.