title: Antibacterial Activity of Ti₃C₂Tx MXene.
abstract: MXenes are a family of atomically thin, two-dimensional (2D) transition metal carbides and carbonitrides with many attractive properties. Two-dimensional Ti3C2Tx (MXene) has been recently explored for applications in water desalination/purification membranes. A major success indicator for any water treatment membrane is the resistance to biofouling. To validate this and to understand better the health and environmental impacts of the new 2D carbides, we investigated the antibacterial properties of single- and few-layer Ti3C2Tx MXene flakes in colloidal solution. The antibacterial properties of Ti3C2Tx were tested against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) by using bacterial growth curves based on optical densities (OD) and colonies growth on agar nutritive plates. Ti3C2Tx shows a higher antibacterial efficiency toward both Gram-negative E. coli and Gram-positive B. subtilis compared with graphene oxide (GO), which has been widely reported as an antibacterial agent. Concentration dependent antibacterial activity was observed and more than 98% bacterial cell viability loss was found at 200 μg/mL Ti3C2Tx for both bacterial cells within 4 h of exposure, as confirmed by colony forming unit (CFU) and regrowth curve. Antibacterial mechanism investigation by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) coupled with lactate dehydrogenase (LDH) release assay indicated the damage to the cell membrane, which resulted in release of cytoplasmic materials from the bacterial cells. Reactive oxygen species (ROS) dependent and independent stress induction by Ti3C2Tx was investigated in two separate abiotic assays. MXenes are expected to be resistant to biofouling and offer bactericidal properties.
authors.affiliation: Qatar Environment and Energy Research Institute (QEERI), Hamad Bin Khalifa University (HBKU) , P.O. Box 5825, Doha, Qatar.
authors.forename: Kashif
authors.initials: K
authors.lastname: Rasool
authors.affiliation: Qatar Environment and Energy Research Institute (QEERI), Hamad Bin Khalifa University (HBKU) , P.O. Box 5825, Doha, Qatar.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Helal
authors.affiliation: Qatar Environment and Energy Research Institute (QEERI), Hamad Bin Khalifa University (HBKU) , P.O. Box 5825, Doha, Qatar.
authors.forename: Adnan
authors.initials: A
authors.lastname: Ali
authors.affiliation: Department of Materials Science and Engineering and A.J. Drexel Nanomaterials Institute, Drexel University , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Chang E
authors.initials: CE
authors.lastname: Ren
authors.affiliation: Department of Materials Science and Engineering and A.J. Drexel Nanomaterials Institute, Drexel University , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Yury
authors.initials: Y
authors.lastname: Gogotsi
authors.affiliation: Qatar Environment and Energy Research Institute (QEERI), Hamad Bin Khalifa University (HBKU) , P.O. Box 5825, Doha, Qatar.
authors.forename: Khaled A
authors.initials: KA
authors.lastname: Mahmoud
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects; D004927:Escherichia coli Infections / Q000517:prevention & control; D006801:Humans; D050296:Microbial Viability / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials; D017382:Reactive Oxygen Species; D014025:Titanium
keywords: B. subtilis; E. coli; MXene; Ti3C2Tx; antibacterial; membrane; oxidative stress