Open AccessAntibacterial effects of carbon dots in combination with other antimicrobial reagents
Author(s) -
Xiuli Dong,
Mohamad Al Awak,
Nicholas Tomlinson,
Yongan Tang,
Ya Ping Sun,
Liju Yang
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0185324
Subject(s) - antimicrobial , bacteria , bacillus subtilis , ethylamine , reagent , minimum inhibitory concentration , antibacterial activity , chemistry , ethylenedioxy , gram negative bacteria , gram positive bacteria , microbiology and biotechnology , biology , escherichia coli , biochemistry , organic chemistry , genetics , alkyl , gene
This study was designed to investigate the antimicrobial effects of CDots in combination with other antimicrobial reagents, including H 2 O 2 , Na 2 CO 3 , and AcOH (acetic acid). CDots were synthesized and passivated with 2,2’-(ethylenedioxy)bis(ethylamine) (EDA). The minimal inhibitory concentration (MIC) of CDots was 64 μg/mL on both Gram negative bacteria E . coli cells and Gram positive bacteria Bacillus subtilis cells. When CDots were combined with H 2 O 2 , antibacterial synergistic effects were observed based on the fractional inhibitory concentration (FIC) index, and further confirmed by an isobologram analysis and viable cell number counting methods. With the combination treatment of 10 μg/mL CDots with 8.82 mM H 2 O 2 , the viable E . coli cell numbers decreased 2.46 log, which was significant lower than the log reduction from 8.82 mM H 2 O 2 (1.57 log) or 10 μg/mL CDots (0.14 log) treatment alone. However, the combination of CDots with Na 2 CO 3 or AcOH did not show synergistic effects, instead, exhibiting indifference effects according to the FIC index. This study indicated that the combination of CDots with their synergistic antimicrobial reagents, such as H 2 O 2 , could reach the goal of inhibiting bacteria growth by using lower concentration of each individual chemical in the combination than using one chemical treatment alone, reduce the risks imposed on environmental health and the possibilities of the development of microbial resistances.