Discipline: Nanoscience
Subcategory: Nanoscience
Session: 3
Room: Park Tower 8228
Abdiel Oquendo - University of Puerto Rico, Mayaguez Campus
Co-Author(s): Oscar Perales, University of Puerto Rico, Mayaguez Campus, Mayaguez PR.
As a consequence of growing water demand and pollution, water borne disease outbreaks are on the rise and current disinfection methods have shown to be ineffective in inactivating all pathogens during water treatment. Zinc oxide nanoparticles (ZnO NPs) have reported antimicrobial properties due to oxidative stress caused by reactive oxygen species (ROS) generation. Also, ZnO has high thermal and chemical stability and low toxicity, which makes these NPs an excellent candidate for water treatment applications. Furthermore, incorporation of lithium (Li) in the crystal structure of ZnO NPs should enhance the production of reactive oxygen species. On the other hand, for practical applications, the nanoparticles must be immobilized in a medium to ensure that particles are not dispersed into the treated water. Accordingly, this work addresses the effect of Li doping on the antibacterial properties of ZnO nanorods synthesized using a polyol-based process. Additionally, synthesized nanoparticles were dispersed in electrospun polyacrylonitrile (PAN) membranes to evaluate antibacterial capacity of the composites. X-Ray Diffraction (XRD) analyses confirmed the wurtzite ZnO phase, while the incorporation of Li in the ZnO structure was evidenced by the systematic shift of the diffraction peaks. The embedding of ZnO nanoparticles to PAN electrospun membranes was also confirmed by XRD. Scanning Electron Microscopy (SEM) characterization was used to determine morphology and size. UV-VIS and Photoluminescence (PL) spectroscopy measurements were used to evaluate the optical properties of the synthesized nanoparticles. Furthermore, the antibacterial activity of pure and doped ZnO NPs was evaluated against E. coli, S. typhimurium and E. faecalis. Minimum inhibitory concentration (MIC) was determined using a simple microdilution method. Also, growth curves of the test bacterium were generated using the colony count method to better elucidate the possible bactericide mechanisms of synthesized nanoparticles and membrane composites. Generation of ROS species was evaluated via photocatalytic experiments using methylene blue dye.
Funder Acknowledgement(s): This project was supported by the National Science Foundation under Grant No. HRD 1345156 (CREST Program).
Faculty Advisor: Oscar Perales, oscarjuan.perales@upr.edu
Role: All experimental work, analysis of data and conclusions.