کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1249559 | 1495974 | 2016 | 10 صفحه PDF | دانلود رایگان |
In this study, we performed the first comparative study of the antibacterial mechanisms of silver ion (Ag+) and silver nanoparticles (AgNPs) on Escherichia coli (E. coli) using Fourier transform infrared (FTIR) spectroscopy. Through a thorough analysis of the FTIR spectra of E. coli after silver treatment in the spectral regions corresponding to thiol group, protein, lipopolysaccharide (LPS), and DNA, we were able to reveal a multifaceted antibacterial mechanism of silver at the molecular level for both Ag+ and AgNPs. Features of such mechanism include: (1) silver complexes with thiol group; (2) silver induces protein misfolding; (3) silver causes loss of LPS from bacterial membrane; (4) silver changes the overall conformation of DNA. Despite the similarities between Ag+ and AgNPs with respect to their antibacterial mechanisms, we further revealed that Ag+ and AgNPs display quite different kinetics for silver-thiol complexation and loss of LPS, with Ag+ displaying fast kinetics and AgNPs displaying slow kinetics. At last, we proposed a hypothesis to interpret the observed different behaviors between Ag+ and AgNPs when interacting with E. coli.
Journal: Vibrational Spectroscopy - Volume 85, July 2016, Pages 112–121