Assembly of Carbon Dots into Frameworks with Enhanced Stability and Antibacterial Activity

Abstract

Carbon dots (CDs) have been widely used as antimicrobials due to their active surface, but some CDs suffer instability. Therefore, the relative applications such as the antibacterial activity may not be reliable for long-term use. Herein, we synthesize CDs with blue fluorescence by a hydrothermal process. Thereafter, polyethylenimine was applied for the assembly of CDs into CDs-based frameworks (CDFs). The CDFs exhibited quenched fluorescence but showed more stable properties based on the scanning electron microscope and zeta potential investigations. Both CDs and CDFs show antibacterial activity toward Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), but CDFs exhibited better antibacterial performance, and S. aureus could be completely inhibited with the minimum inhibitory concentration of 30 μg/mL. This reveals CDFs magnify both the stability and antibacterial activity, which would be more promising for practical applications. Graphic abstract

Photothermal synergistic nitric oxide controlled release injectable self-healing adhesive hydrogel for biofilm eradication and wound healing

“…71 FDA could be decomposed by lipases and produce fluorescein, thereby viable and intact cells produce green fluorescence. 72,73 As illuminated in Fig. 7D, all of the bacteria in the untreated Control group showed strong green fluorescence and displayed a dense and intact biofilm with a thickness of about 16 μm.…”

Low-Toxicity Antibacterial Carbon Nanodots for Wound Dressings and Food Packaging

“…When it is of interest, the assembly of CDs is usually achieved with an added linker agent. For example, Zhuang et al have reported that “polyethylenimine was applied for the assembly of CDs into CDs-based frameworks (CDFs),” which exhibit enhanced antibacterial activities . The morphology of the current CDs is examined by TEM, and the results are shown in Figure .…”

“…For example, Zhuang et al have reported that "polyethylenimine was applied for the assembly of CDs into CDs-based frameworks (CDFs)," which exhibit enhanced antibacterial activities. 43 The morphology of the current CDs is examined by TEM, and the results are shown in Figure 2. Both species of CDs appear as self-assembled clusters of carbon particles.…”