The rising prevalence of microorganisms resistant to antibiotics threatens the effectiveness of conventional antibiotics. The graphene oxide–silver (GO–Ag) nanocomposites have attracted significant interest as a substitute for antibacterial material. Producing uniformly distributed silver nanoparticles (Ag NPs) on graphene oxide (GO) sheets remains a significant challenge. This research investigates the impact of varying reaction times on the chemical reduction process used to create Ag NPs decorated GO sheets and evaluates their antibacterial properties. The GO was prepared using a modified Hummer’s method, followed by the deposition of Ag NPs onto the GO sheets by reducing AgNO<InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="12668_2025_2023_Article_IEq1.gif" Format="GIF" Height="10" Rendition="HTML" Resolution="72" Type="Linedraw" Width="8" /> </InlineMediaObject> <EquationSource Format="TEX">$ _3 $</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>3</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation> using NaBH<InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="12668_2025_2023_Article_IEq2.gif" Format="GIF" Height="10" Rendition="HTML" Resolution="72" Type="Linedraw" Width="8" /> </InlineMediaObject> <EquationSource Format="TEX">$ _4 $</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>4</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation> for three reaction times, 24 h, 48 h, and 72 h. Ag NPs are agglomerated on the GO sheets for 24 h reaction time. Ag NPs are well decorated on the GO sheets for 48 h reaction time. However, the decoration is poor at a very high reaction time, 72 h. The average Ag nanoparticle’s size (9.8 ± 3.6 nm) is lowest for nanocomposites prepared with the 48 h reaction time. Our study shows that a moderate reaction time is required for excellent decoration of the Ag NPs, which is 48 h, and these nanocomposites also have antibacterial activity against the gram-negative bacteria Escherichia coli (E. coli) and gram-positive bacteria Bacillus subtilis (B. subtilis) for low dosages as compared to the other two nanocomposites.

Effect of Reaction Time on Silver Decorated Graphene–Oxide Sheets and Its Antibacterial Activity

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发表日期：

2025年6月10日

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Mamata,
Priti,
Mukta Kulshrestha,
Vishvanath Tiwari,
Anirban Dutta

摘要

The rising prevalence of microorganisms resistant to antibiotics threatens the effectiveness of conventional antibiotics. The graphene oxide–silver (GO–Ag) nanocomposites have attracted significant interest as a substitute for antibacterial material. Producing uniformly distributed silver nanoparticles (Ag NPs) on graphene oxide (GO) sheets remains a significant challenge. This research investigates the impact of varying reaction times on the chemical reduction process used to create Ag NPs decorated GO sheets and evaluates their antibacterial properties. The GO was prepared using a modified Hummer’s method, followed by the deposition of Ag NPs onto the GO sheets by reducing AgNO $ _3 $ $_{3}$ using NaBH $ _4 $ $_{4}$ for three reaction times, 24 h, 48 h, and 72 h. Ag NPs are agglomerated on the GO sheets for 24 h reaction time. Ag NPs are well decorated on the GO sheets for 48 h reaction time. However, the decoration is poor at a very high reaction time, 72 h. The average Ag nanoparticle’s size (9.8 ± 3.6 nm) is lowest for nanocomposites prepared with the 48 h reaction time. Our study shows that a moderate reaction time is required for excellent decoration of the Ag NPs, which is 48 h, and these nanocomposites also have antibacterial activity against the gram-negative bacteria Escherichia coli (E. coli) and gram-positive bacteria Bacillus subtilis (B. subtilis) for low dosages as compared to the other two nanocomposites.