title: Thiol-Capped Gold Nanoparticles Swell-Encapsulated into Polyurethane as Powerful Antibacterial Surfaces Under Dark and Light Conditions.
abstract: A simple procedure to develop antibacterial surfaces using thiol-capped gold nanoparticles (AuNPs) is shown, which effectively kill bacteria under dark and light conditions. The effect of AuNP size and concentration on photo-activated antibacterial surfaces is reported and we show significant size effects, as well as bactericidal activity with crystal violet (CV) coated polyurethane. These materials have been proven to be powerful antibacterial surfaces against both Gram-positive and Gram-negative bacteria. AuNPs of 2, 3 or 5 nm diameter were swell-encapsulated into PU before a coating of CV was applied (known as PU-AuNPs-CV). The antibacterial activity of PU-AuNPs-CV samples was tested against Staphylococcus aureus and Escherichia coli as representative Gram-positive and Gram-negative bacteria under dark and light conditions. All light conditions in this study simulated a typical white-light hospital environment. This work demonstrates that the antibacterial activity of PU-AuNPs-CV samples and the synergistic enhancement of photoactivity of triarylmethane type dyes is highly dependent on nanoparticle size and concentration. The most powerful PU-AuNPs-CV antibacterial surfaces were achieved using 1.0 mg mL-1swell encapsulation concentrations of 2 nm AuNPs. After two hours, Gram-positive and Gram-negative bacteria were reduced to below the detection limit (>4 log) under dark and light conditions.
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Macdonald
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom.
authors.forename: Ke
authors.initials: K
authors.lastname: Wu
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom.
authors.forename: Sandeep K
authors.initials: SK
authors.lastname: Sehmi
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom.
authors.forename: Sacha
authors.initials: S
authors.lastname: Noimark
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom.
authors.forename: William J
authors.initials: WJ
authors.lastname: Peveler
authors.affiliation: Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, United Kingdom.
authors.forename: Hendrik
authors.initials: H
authors.lastname: du Toit
authors.affiliation: ARC Centre of Excellence for Convergent Bio-Nano Science and Technology, Future Industries Institute, University of South Australia, Mawson Lakes, 5095, Australia.
authors.forename: Nicolas H
authors.initials: NH
authors.lastname: Voelcker
authors.affiliation: Division of Microbial Diseases, UCL Eastman Dental Institute, University College London, 256 Grays Inn Road, London, WC1X 8LD, United Kingdom.
authors.forename: Elaine
authors.initials: E
authors.lastname: Allan
authors.affiliation: UCL Division of Surgery and Interventional Science, Royal Free Campus, Rowland Hill Street, London, NW3 2PF, United Kingdom.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: MacRobert
authors.affiliation: Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, United Kingdom.
authors.forename: Asterios
authors.initials: A
authors.lastname: Gavriilidis
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom.
authors.forename: Ivan P
authors.initials: IP
authors.lastname: Parkin
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D005840:Gentian Violet / Q000737:chemistry / Q000494:pharmacology; D006046:Gold / Q000737:chemistry*; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D056951:Photoelectron Spectroscopy; D011140:Polyurethanes / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000900:Anti-Bacterial Agents; D011140:Polyurethanes; D013438:Sulfhydryl Compounds; D006046:Gold; D005840:Gentian Violet