Observing antimicrobial process with traceable gold nanoclusters
- PDF / 3,364,899 Bytes
- 8 Pages / 612 x 808 pts Page_size
- 60 Downloads / 205 Views
Observing antimicrobial process with traceable gold nanoclusters Kaiyuan Zheng1, Magdiel I. Setyawati2, David Tai Leong1 (), and Jianping Xie1 () 1 2
Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
© Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature 2020 Received: 28 August 2020 / Revised: 23 September 2020 / Accepted: 24 September 2020
ABSTRACT Understanding the interaction of nanomaterials with biological systems has always been of high concern and interest. An emerging type of nanomaterials, ultrasmall metal nanoclusters (NCs, < 2 nm in size), are promising in this aspect due to their well-defined molecular formulae and structures, as well as unique physical and chemical properties that are distinctly different from their larger counterparts (metal nanoparticles). For example, metal NCs possess intrinsic strong luminescence, which can be used for real-time tracking of their interactions with biological systems. Herein, luminescent gold (Au) NCs were used as traceable antimicrobial agents to study their interactions with the bacteria and to further understand their underlining antimicrobial mechanism. It is shown for the first time that the Au NCs would first attach on the bacterial membrane, penetrate, and subsequently accumulate inside the bacteria. Thereafter, the internalized Au NCs would induce reactive oxygen species (ROS) generation and damage the bacterial membrane, resulting in the leakage of bacterial contents, which can finally kill the bacteria. Traceable Au NCs (or other metal NCs) provide a promising platform to study the antimicrobial mechanisms as well as other fundamentals on the interfacing of functional nanomaterials with the biological systems, further increasing their acceptance in various biomedical applications.
KEYWORDS metal nanoclusters, gold nanoclusters, antimicrobial agents, luminescent probes, bioimaging
1
Introduction
The rapid development of nanotechnology has produced a wealth of emerging nanomaterials (NMs), of which their interactions with any biological system are inevitable. Understanding how these NMs interact with the biological systems becomes pivotal, as it lends the material scientists the capability in modulating the biological outcomes through the NMs design [1–8]. The emerging ultrasmall metal nanoparticles (NPs), also known as metal nanoclusters (NCs), are comprised of several to a hundred metal atoms with core size below 2 nm [9]. Due to their ultrasmall size, these metal NCs exhibit unique molecule-like physicochemical properties, such as well-defined molecular formulae and structures, quantized charging, highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) transitions, molecular magnetism, molecular chirality, and strong luminescence, which are distinctly different from their lar
Data Loading...
