One-step synthesized antimicrobial peptide-functionalized gold nanoclusters for selective imaging and killing of pathogenic bacteria

• Published in: Frontiers in microbiology Vol. 13; p. 1003359
• Main Authors: Shen, Yunqiu, Zheng, Chaochuan, Wu, Qiaoli, Wu, Qilong, Jin, Ming, Jiang, Yayun, Huang, Fuyuan, Lou, Yongliang, Zheng, Laibao
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 10-10-2022
• Subjects: antimicrobial peptide; bacteria killing; bacterial infection; gold nanocluster; Microbiology; nanomaterials; selective imaging
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2022.1003359

The development of multifunctional nanomaterials with bacterial imaging and killing activities is of great importance for the rapid diagnosis and timely treatment of bacterial infections. Herein, peptide-functionalized gold nanoclusters (CWR11-AuNCs) with high-intensity red fluorescence were successfully synthesized
via
a one-step method using CWR11 as a template and by optimizing the ratio of CWR11 to HAuCl4, reaction time, pH, and temperature. The CWR11-AuNCs bound to bacteria and exhibited selective fluorescence microscopy imaging properties, which is expected to provide a feasible method for locating and imaging bacteria in complex
in vivo
environments. In addition, CWR11-AuNCs not only retained the antibacterial and bactericidal activities of CWR11 but also exhibited certain inhibitory or killing effects on gram-negative and gram-positive bacteria and biofilms. The MICs of CWR11-AuNCs against
Escherichia coli
and
Staphylococcus aureus
were 178 and 89 μg/ml, respectively. Surprisingly, cell viability in the CWR11-AuNC-treated group was greater than that in the CWR11-treated group, and the low cytotoxicity exhibited by the CWR11-AuNCs make them more promising for clinical applications.