Transparent, Robust, and Photochemical Antibacterial Surface Based on Hydrogen Bonding between a Si-Al and Cationic Dye

Abstract

Healthcare-associated infections can occur and spread through direct contact with contaminated fomites in a hospital, such as mobile phones, tablets, computer keyboards, doorknobs, and other surfaces. Herein, this study shows a transparent, robust, and visible light-activated antibacterial surface based on hydrogen bonds between a transparent silica-alumina (Si-Al) sol−gel and a visible light-activated photosensitizer, such as crystal violet (CV). The study of the bonding mechanisms revealed that hydrogen bonding predominantly occurs between the N of CV and Al-OH. Apart from CV, Si-Al can be combined with a variety of dyes, highlighting its potential for wide application. The Si-Al@CV film selectively generates singlet oxygen using ambient visible light, triggering potent photochemical antibacterial performance against Gram-positive and Gram-negative bacteria. Additionally, the Si-Al@CV film is stable even after mechanical stability tests such as tape adhesion, scratch, bending, and water immersion. In vitro cytotoxicity tests using C2C12 myoblast cells showed that the Si-Al@CV film is a biocompatible material. This work suggests a new approach for designing a transparent and robust touchscreen surface with photochemical antibacterial capability against healthcareassociated infections.

Antimicrobial and Antifouling Effects of Petal‐Like Nanostructure by Evaporation‐Induced Self‐Assembly for Personal Protective Equipment

“…[ 27,28 ] This indicates a shift toward a lower binding energy, which is attributed to the electron‐withdrawing effect facilitated by hydrogen bonding with the amino group of ODA (Figure 1b(i)), in accordance with previous studies. [ 29 ] This conclusion is corroborated by the corresponding high‐resolution Si 2p spectra. [ 29 ] Thus, compared to those of the non‐coated specimens, the XPS of the PNS‐coated specimens featured peaks at lower binding energies, indicating that the lamellar bilayer formation was supported by extensive bonding with ODA (Figure 1e).…”

“…[29] This conclusion is corroborated by the corresponding highresolution Si 2p spectra. [29] Thus, compared to those of the non-coated specimens, the XPS of the PNS-coated specimens featured peaks at lower binding energies, indicating that the lamellar bilayer formation was supported by extensive bonding with ODA (Figure 1e).…”

“…Preparation of the PS@PNS-Coated Specimens: The Sol solution was synthesized according to previously reported literature. [18,29] A certain wt% of ODA (99.5%, Sigma Aldrich), Sol, and PSs (RB, EoY, SCC, Methylene blue (MB), Crystal violet (CV), Toluidine blue O (TBO); Sigma Aldrich) were fully dissolved in acetone (99.7%, Daejung, Republic of Korea) at 50 ˚C for 30 min. Then, the coating solution was stored at 25 °C in a dark chamber to avoid light exposure.…”