Bioavailability of Silver Nanoparticles Based on Flurorescent Bacterial Sensor
Escherichia coli expressing recombinant green fluorescent protein (GFP) was used as a model system to evaluate the bioavailability of fresh AgNPs and AgNPs aged in sodium chloride (NaCl).The antibacterial activity of fresh AgNPs was measured using E.coli exposed to a concentration gradient of 0, 0.5, 1 and 2 μg/mL for 10 h with microplate reader, fluorescence microscope, flow cytometer and plasmid extraction kit.Aged AgNPs was obtained by exposing fresh AgNPs in a series of NaCl solutions with molar ratio of Cl/Ag as 0, 100, 500, 800 for 12 days characterized by UV-Vis spectrophotometer.The antimicrobial effect of aged AgNPs and supernatants was statistically analyzed through the inhibition rate of GFP which was detected by flow cytometer and microplate reader on exposed E.coli (10 h).The results showed that AgNPs could significantly decrease the fluorescence intensity of GFP in E.coli and inhibit plasmid DNA replication.The presence of chloride ions can accelerate the dissolution of AgNPs.E.coli increased tolerance to AgNPs pretreated with high Cl/Ag ratio solution.
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万方数据
维普
