Ionic Content Reduction and Aspect Ratio Control in Nanoconfined Silver Citrate Nanoparticles through Redox...

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Silver-based biomaterials face challenges with chemical instability and uncontrolled ion release, limiting their safety applications.
• Developing stable silver nanostructures with controlled ion release is crucial for effective antimicrobial materials.

Purpose of the Study:

• To synthesize silver citrate nanorods (Ag-Cit) with reduced agglomeration and controlled properties.
• To investigate the influence of synthesis reaction time on Ag-Cit characteristics and antibacterial efficacy.
• To determine the optimal stage for ionic reduction and antibacterial activity in Ag-Cit synthesis.

Main Methods:

• Ag-Cit nanorods were synthesized using a sodium citrate method at 60 °C with reaction times from 1 to 5 hours.
• Characterization involved XRD, DSC, TEM, DLS, SEM, UV-vis, FTIR, and XPS/EPM.
• Antimicrobial activity was assessed using antibiotic assay disk and time-kill curve assays against E. coli and S. aureus.

Main Results:

• Synthesis time influenced Ag-Cit properties, with the 5-hour sample showing enhanced crystallinity and aspect ratio.
• The 5-hour sample achieved over 50% silver ion reduction and electrical neutrality.
• Both bacteriostatic and bactericidal activities were strongest in the 1-hour (larger size) and 5-hour (higher aspect ratio) samples.
• Brown coloration of colloidal solutions indicated optimal Ag-Cit stability.

Conclusions:

• Synthesis reaction time is a critical factor in tuning the properties and antibacterial effectiveness of silver citrate nanorods.
• Ag-Cit compounds synthesized for optimal stability (indicated by brown color) show promising antimicrobial potential.
• This research provides a foundation for developing stable, low ionic content antimicrobial materials based on Ag-Cit nanorods.