Document Type : Original Paper


1 1 Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran

2 2 Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran

3 3 Antimicrobial Resistance Research Center, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Islamic Republic of Iran

4 1 Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran and 2 Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran


Silver nanoparticles (AgNPs) are well-known nanomaterials that have been mainly used as antimicrobial agents Hundreds of chemical or biological methods have been reported and described for the preparation of AgNPs in water so far. Aqueous colloids of AgNPs normally have a limited capacity to safely change to the concentrated form using conventional methods such as different evaporation methods. Organic solvents which could be easily evaporated using conventional evaporation vacuum methods are good candidates for the preparation of highly concentrated AgNPs formulations or dried concentrates. In this study, we used a previously described biological method for preparing AgNPs in an acetone-water solvent mixture. The nanoparticles were synthesized using culture supernatant of Klebsiella pneumonia in the above organic solvent mixture supplemented with polyethylene glycol 6000 in a bright condition and subsequently dried by a conventional evaporation method. In the next step, dried residues were re-dispersed in water under ultra-sound treatment and characterized with different instrumentation methods. The results showed spherical AgNPs with a size range of ≤ 200 nm. This is the first report on the biological synthesis of AgNPs in an organic solvent mixture which could be easily converted to a dried form. This dried AgNPs concentrate is a good candidate for the preparation of very thick formulations of AgNPs such as solid or semi-solid pastes.


  1. .    Caputo F, Clogston J, Calzolai L, Rösslein M, Prina-Mello A. Measuring particle size distribution of nanoparticle enabled medicinal products, the joint view of EUNCL and NCI-NCL. A step by step approach combining orthogonal measurements with increasing complexity. J. Control. Release. 2019;299:31-43.

    1. Jamkhande PG, Ghule NW, Bamer AH, Kalaskar MG. Metal nanoparticles synthesis: An overview on methods of preparation, advantages and disadvantages, and applications. J. Drug Deliv. Sci. Technol. 2019;53:101174.
    2. Yonezawa T. Application 78 - Preparation of metal nanoparticles and their application for materials. In: Naito M, Yokoyama T, Hosokawa K, Nogi K, editors. Nanoparticle Technology Handbook (Third Edition): Elsevier; 2018. p. 829-37.
    3. Khan I, Saeed K, Khan I. Nanoparticles: Properties, applications and toxicities. Arab. J. Chem. 2019;12(7):908-31.
    4. Yaqoob AA, Ahmad H, Parveen T, Ahmad A, Oves M, Ismail IMI, et al. Recent advances in metal decorated nanomaterials and their various biological applications: A review. Front. Chem. 2020;8(341).
    5. Miranda RR, Sampaio I, Zucolotto V. Exploring silver nanoparticles for cancer therapy and diagnosis. Colloid. Surf. B: Biointerfaces. 2022;210:112254.
    6. Bouafia A, Laouini SE, Ahmed ASA, Soldatov AV, Algarni H, Feng Chong K, et al. The recent progress on silver nanoparticles: Synthesis and electronic applications. nanomaterials (Basel). 2021;11(9).


    1. Dong X-Y, Gao Z-W, Yang K-F, Zhang W-Q, Xu L-W. Nanosilver as a new generation of silver catalysts in organic transformations for efficient synthesis of fine chemicals. Catal. Sci. Technol. 2015;5(5):2554-74.
    2. Bamal D, Singh A, Chaudhary G, Kumar M, Singh M, Rani N, et al. Silver nanoparticles biosynthesis, characterization, antimicrobial activities, applications, cytotoxicity and safety issues: An updated review. Nanomaterials. 2021;11(8).
    3. Almatroudi A. Silver nanoparticles: synthesis, characterisation and biomedical applications. Open Life Sci. 2020;15(1):819-39.
    4. Iravani S, Korbekandi H, Mirmohammadi SV, Zolfaghari B. Synthesis of silver nanoparticles: chemical, physical and biological methods. Res. Pharm. Sci. 2014;9(6):385-406.
    5. Shankar R, Groven L, Amert A, Whites KW, Kellar JJ. Non-aqueous synthesis of silver nanoparticles using tin acetate as a reducing agent for the conductive ink formulation in printed electronics. J. Mater. Chem. 2011;21(29):10871-7.
    6. Oliveira R, Bizeto M, Liberatore A, Koh I, Camilo F. A new method for producing highly concentrated non-aqueous dispersions of silver nanoparticles and the evaluation of their bactericidal activity. J. Nanoparticle Res. 2014;16.
    7. Shahverdi AR, Minaeian S, Shahverdi H, Jamalifar H, Nohi A-A. Rapid synthesis of silver nanoparticles using culture supernatants of Enterobacteria: A novel biological approach. Process Biochem. 2007;42:919-23.
    8. Shahverdi AR, Fakhimi A, Shahverdi HR, Minaian S. Synthesis and effect of silver nanoparticles on the antibacterial activity of different antibiotics against Staphylococcus aureus and Escherichia coli. Nanomedicine. 2007;3(2):168-71.
    9. Karmakar S. Particle size distribution and zeta potential based on dynamic light scattering: Techniques to characterise stability and surface distribution of charged colloids. Recent trends in materials physics and chemistry. Studium Press (India) Pvt Ltd, 2019. 117-59.
    10. Rahdar A, Amini N, Askari F, Susan MABH. Dynamic light scattering: A useful technique to characterize nanoparticles. J. Nanoanalysis. 2019;6(2):80-9.
    11. Havrdova M, Polakova K, Skopalik J, Vujtek M, Mokdad A, Homolkova M, et al. Field emission scanning electron microscopy (FE-SEM) as an approach for nanoparticle detection inside cells. Micron. 2014;67:149-54.
    12. Jayaramudu T, Raghavendra GM, Varaprasad K, Subba Reddy G, Reddy A, Sudhakar K, et al. Preparation and characterization of poly (ethylene glycol) stabilized nano silver particles by a mechanochemical assisted ball mill process. J. Appl. Polym. Sci. 2016;133:43027.
    13. Shi L, Zhang J, Zhao M, Tang S, Cheng X, Zhang W, et al. Effects of polyethylene glycol on the surface of nanoparticles for targeted drug delivery. Nanoscale. 2021;13(24):10748-64.