Photoactive Antimicrobial CuZnO Nanocrystals

Abstract

Semiconductor nanocrystals (NCs) are promising photocatalysts due to their high surface area to volume ratio and tunable physicochemical properties. Of particular interest are earthabundant metal oxides, such as ZnO and CuO, which are stable under ambient conditions and in aqueous media and are environmentally and biologically compatible. While CuO NCs are efficient catalytic and antimicrobial materials featuring strong and broad absorption in the visible region, their challenging surface chemistry and low colloidal stability so far limited their wide implementation as photocatalysts. On the other hand, colloidal ZnO NCs function as excellent photocatalysts in various media, but their absorption is limited to the UV region. Herein, colloidal antimicrobial Cu 1−x Zn x O NCs are synthesized via a facile and cost-effective method, forming a unique spatial dependent structure and composition, with higher zinc concentration on the surface. The doped NCs show enhanced antimicrobial activity increasing with higher amount of dopant. Furthermore, the NCs exhibit superior antimicrobial activity upon visible light illumination effectively eradicating even multidrug resistant bacteria, due to increased ion migration and photocatalytic formation of reactive oxygen species. Such Cu 1−x Zn x O NCs, therefore, show promise as biocompatible antimicrobial materials that can be utilized under ambient conditions in diverse scenarios enabled by wet chemical processing.

ZnO Quantum Photoinitiators as an All-in-One Solution for Multifunctional Photopolymer Nanocomposites

“…8−11 While their optical functionality has already been addressed in numerous studies and brought to real-life applications, 8,12−14 the utilization and multifunctional outcomes of photocatalytic SCNCs in such nanocomposites have not yet been sufficiently addressed. 4,15,16 Herein we investigate the multifunctionality of ZnO nanocrystals as a model for photocatalytic SCNCs acting as photoinitiators in acrylate-based polymers, where they function as a photocatalytic radical initiator and endow the system with mechanical, photocatalytic, and antimicrobial properties.…”

“…Polymer nanocomposites are constructed from a continuous polymeric matrix material combined with a nanosized property-modifying filler. This diverse and flexible combination yields the powerful ability to tailor the desired mechanical, optical, electrical, physical, and antimicrobial material properties. − Colloidal semiconductor nanocrystals (SCNCs) are very interesting fillers, as they showcase size-, shape-, and composition-controlled properties and can be easily embedded in a variety of matrices. − While their optical functionality has already been addressed in numerous studies and brought to real-life applications, ,− the utilization and multifunctional outcomes of photocatalytic SCNCs in such nanocomposites have not yet been sufficiently addressed. ,, Herein we investigate the multifunctionality of ZnO nanocrystals as a model for photocatalytic SCNCs acting as photoinitiators in acrylate-based polymers, where they function as a photocatalytic radical initiator and endow the system with mechanical, photocatalytic, and antimicrobial properties.…”

“…Subsequent global concern over this worrying trend, along with additional bacterial and viral threats, has created a demand for efficient antimicrobial agents. Examples of solutions utilized heretofore include Ag nanoparticles (NPs), quaternized amines, and metal oxides, among others, which have a wide antibacterial spectrum. , Ag NPs, in fact, possess one of the highest levels of antibacterial activity in biomedical applications. However, the drawback of Ag NPs is the continuous dissolution and formation of Ag + , which is toxic to biological systems, even at very low concentrations .…”