A comparative evaluation of green colloidal silver variants for enhanced stability and bioactivity

Trotta, F., Winning, D., Sadiatoonasa, S., Mirpoor, S. F. ORCID: https://orcid.org/0000-0001-9172-794X, Lignou, S. ORCID: https://orcid.org/0000-0001-6971-2258, Khalil Ghawi, S. and Charalampopoulos, D. ORCID: https://orcid.org/0000-0003-1269-8402 (2025) A comparative evaluation of green colloidal silver variants for enhanced stability and bioactivity. Scientific Reports. ISSN 2045-2322 doi: 10.1038/s41598-025-30332-7 (In Press)

Abstract/Summary

Colloidal silver (CS) is at the forefront of enhancing novel consumer products formulations & packaging. However, conventional synthesis methods pose challenges, including toxicity, high costs, and poor colloidal stability. Green synthesis using plant extracts offers a sustainable alternative by leveraging natural bioactive compounds. This study compares CS synthesized via a patented plant-based method (CS BX3 ), Lemon Juice (CS LJ ), and Green Tea (CS GT ), with a commercial reference (CS Ref ). Characterization using UV–Vis, DLS, SEM, Zeta Potential, and EDS assessed particle size, stability, and composition under stress conditions: long-term storage (60 days), varying temperatures (4–37 °C), pH (3–11), and phosphate-buffered saline (PBS). Antioxidant activity was evaluated and antimicrobial efficacy against E.coli and Listeria to determine MIC. CS BX3 and CS LJ showed superior stability under various stress conditions CS BX3 retained colloidal stability both at low temperatures (3.97% size reduction at 4 °C) and in PBS (14.2% in SPR intensity). CS LJ displayed strong steric stabilization, showing minimal size variation in PBS. Zeta potential and SEM analyses confirmed that CS BX3 maintained dispersion and particle uniformity across neutral and alkaline pH, while CS GT showed significant aggregation . CS GT and CS BX3 showed the most potent antimicrobial and antioxidant properties (20% higher antioxidant activity than other CS solutions and over 90% bacterial eradication within 24 h). These results highlight the potential of green-synthesized CS for food, biomedical, and personal care applications.

Item Type	Article
URI	https://centaur.reading.ac.uk/id/eprint/127605
Identification Number/DOI	10.1038/s41598-025-30332-7
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Food and Nutritional Sciences > Food Research Group
Publisher	Nature Publishing Group
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