Essential oil-incorporated carbon nanotubes filters for bacterial removal and inactivation

• Published in: PloS one Vol. 14; no. 12; p. e0227220
• Main Authors: Dong, Xiuli, Bond, Ambrose E, Yang, Liju
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27.12.2019; Public Library of Science (PLoS)
• Subjects: Acids; Anti-Bacterial Agents - administration & dosage; Anti-Bacterial Agents - pharmacology; Antiinfectives and antibacterials; Antimicrobial agents; Aqueous solutions; Bacteria; Biology and Life Sciences; Carbon; Carcinogens; Chlorine; Coatings; Deactivation; Disinfection & disinfectants; Drinking water; Drug Carriers - chemistry; E coli; Engineering and Technology; Escherichia coli - drug effects; Escherichia coli - isolation & purification; Escherichia coli Infections - microbiology; Escherichia coli Infections - prevention & control; Essential oils; Filters; Humans; Inactivation; Lemons; Medicine and Health Sciences; Membrane filters; Microorganisms; Multi wall carbon nanotubes; Nanomaterials; Nanotechnology; Nanotubes; Nanotubes, Carbon - chemistry; Oils & fats; Pathogens; Pharmaceutical sciences; Physical Sciences; Plant Oils - administration & dosage; Plant Oils - pharmacology; Pore size; Salt tolerance; Sodium chloride; Tea Tree Oil - administration & dosage; Tea Tree Oil - pharmacology; Tolerances; Waterborne diseases; North Carolina; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0227220

In this study, essential oils (EO)-incorporated multi-walled carbon nanotubes (MWCNTs) filters were developed for achieving dual functions in effective removing bacteria from aqueous solutions and inactivating bacteria cells captured on the filters. Tea tree essential oil (TTO), lemon essential oil (LEO), and TTO-LEO-mixture were coated on MWCNTs filters with different MWCNTs loadings ranging from 3 mg to 6 mg. MWCNTs filters with 6.0 mg MWCNTs showed complete removal (100%) of E. coli cells from PBS buffer with 6.35 log10 decrease of cell numbers. TTO, LEO, and TTO/LEO Mix (1:1) coatings at the volume of 50 μL on MWCNTs filters achieved bacterial removal rates of >98%, and highly effective inactivation efficiency. TTO coatings had the highest antimicrobial efficacies than LEO and Mix coatings, MWCNTs filters with 50 μL TTO coating showed 100% inhibitory rate of the captured bacteria on the filter surfaces. Those captured but survived cells on filters with less TTO coating (20μL) significantly reduced their salt tolerances to 30 and 40 g/L NaCl in LB agar, and became less salt tolerance with longer incubation time on the filters. The developed TTO-MWCNTs filters had much higher antimicrobial efficacies than the filters with dual functions developed previously.