Ionic Liquid-Functionalized Multiwalled Carbon Nanotube-Based Hydrophobic Coatings for Robust Antibacterial Applications

Deepak Bains; Gagandeep Singh; Jasdeep Bhinder; Prabhat K Agnihotri; Narinder Singh

doi:10.1021/acsabm.9b01217

Ionic Liquid-Functionalized Multiwalled Carbon Nanotube-Based Hydrophobic Coatings for Robust Antibacterial Applications

ACS Appl Bio Mater. 2020 Apr 20;3(4):2092-2103. doi: 10.1021/acsabm.9b01217. Epub 2020 Mar 18.

Authors

Deepak Bains¹, Gagandeep Singh¹, Jasdeep Bhinder², Prabhat K Agnihotri², Narinder Singh¹

Affiliations

¹ Department of Chemistry, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001, India.
² Department of Mechanical Engineering, Indian Institute of Technology Ropar (IIT Ropar) Rupnagar, Punjab 140001, India.

PMID: 35025261
DOI: 10.1021/acsabm.9b01217

Abstract

In recent years, the biomimetic superhydrophobic coatings have received tremendous attention, owing to their potential in fabricating self-cleaning surfaces, in environmental applications. Consequently, extensive research has been devoted to create a superhydrophobic surface using the oxidized derivatives of CNTs and graphene. Thus, the design and development of a self-cleaning/superhydrophobic surface with good biocompatibility are an effective approach to deal with the bacterial infections related to biomedical devices used in hospitals. In this context, herein, we have developed the material based on ionic liquid (IL)-functionalized multiwalled carbon nanotubes (MWCNTs) for hydrophobic coatings, which was fully characterized with various techniques such as Fourier transform infrared, powder X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. We have evaluated the synthesized ILs for their antibacterial potential against the pathogenic bacterial strains such as Gram-positive (Staphylococcus aureus and methicillin-resistant S. aureus) and Gram-negative (Escherichia coli) bacterial strains. Further, atomic force and scanning electron microscopic studies have been performed to investigate the morphological changes to unravel the mechanism of action, whereas DNA binding study indicates the binding of IL-1d@MWCNT with DNA (K_a = 2.390 × 10⁴ M^-1). Furthermore, the developed material (IL-1d@MWCNT) is coated onto the surface of polyvinyl chloride (PVC) and evaluated for hydrophobicity through water contact angle measurements and possesses long-term antibacterial efficiency against both under-investigating pathogenic strains. For the biocompatibility assay, the obtained coated PVC material has also been evaluated for its cytotoxicity, and results reveal no toxicity against viable cells. These all results are taken together, indicating that by coating with the developed material IL-1d@MWCNT, a robust self-sterilizing surface has achieved, which helps in maintaining a bacteria-free surface.

Keywords: hydrophobicity and antibacterial activity; ionic liquids (ILs); multiwalled carbon nanotubes (MWCNTs); polyvinyl chloride (PVC).