Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2021 Dec 16;11(12):3407.
doi: 10.3390/nano11123407.

From Impure to Purified Silver Nanoparticles: Advances and Timeline in Separation Methods

Catarina S M Martins  1 , Helena B A Sousa  1 , João A V Prior  1
Affiliations
Review

From Impure to Purified Silver Nanoparticles: Advances and Timeline in Separation Methods

Catarina S M Martins et al. Nanomaterials (Basel). .

Abstract

AgNPs have exceptional characteristics that depend on their size and shape. Over the past years, there has been an exponential increase in applications of nanoparticles (NPs), especially the silver ones (AgNPs), in several areas, such as, for example, electronics; environmental, pharmaceutical, and toxicological applications; theragnostics; and medical treatments, among others. This growing use has led to a greater exposure of humans to AgNPs and a higher risk to human health and the environment. This risk becomes more aggravated when the AgNPs are used without purification or separation from the synthesis medium, in which the hazardous synthesis precursors remain unseparated from the NPs and constitute a severe risk for unnecessary environmental contamination. This review examines the situation of the available separation methods of AgNPs from crude suspensions or real samples. Different separation techniques are reviewed, and relevant data are discussed, with a focus on the sustainability and efficiency of AgNPs separation methods.

Keywords: AgNPs; purification; separation; silver nanoparticles; synthesis.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Scheme representative of asymmetric-flow field-flow fractionation. Reproduced from Ref. [30] with permission from Frontiers in Chemistry.
Figure 2
Figure 2
Size distributions of AgNPs by two different approaches: (i) size calibration using polystyrene beads (PSNPs) and (ii) conversion of retention times on AF4 analysis to diameters by AF4 theoretical calculations. Reprinted from [27] copyright (2013), with permission from Elsevier.
Figure 3
Figure 3
TEM images corresponding to collected fractions of AgNPs separated by AF4 at the conditions: minj = 10 µg, carrier liquid (NH4)2CO3 at pH 9, channel and cross flow rate 1.0 mL/min, spacer height 350 µm, PES membrane. Reprinted from [27] copyright (2013), with permission from Elsevier.
Figure 4
Figure 4
Schematic representation of the on-line coupled HF5/MCC-UV/DLS/ICPMS analytical system. Reprinted from [29] copyright (2015), with permission from ACS (further permission should be directed to the ACS).
Figure 5
Figure 5
Representative scheme of SEC.
Figure 6
Figure 6
(a) TEM image of AgNPs sample and graphical distribution of the different shapes of the nanoparticles; (b) photograph of an agarose gel run for separation of nanoparticles (0.2% agarose, 30 min run, 150 V, 0.5× TBE buffer); (c) separated fractions of silver nanoparticles in agarose gel and their extinction spectra. Reprinted and adapted with permission from [46], copyright (2007) American Chemical Society.
Figure 7
Figure 7
Separation of AgNPs by shape, monitored by UV–Vis spectrophotometry, after two sequences of selective precipitation. Reprinted from [54], copyright (2018), with permission from Elsevier.
Figure 8
Figure 8
Representative scheme of CPE protocol.
Figure 9
Figure 9
Separation of AgNPs by Triton X-114-based CPE. Reproduced from Ref. [63] with permission from the Royal Society of Chemistry.
Figure 10
Figure 10
Timeline of separation methods: graphic representation of the number of published articles discriminated by separation method (separation methods: Mag—magnetic-based schemes; HyF—hydrodynamic forces; Chr—chromatography; DGC—density gradient centrifugation; Ele—electrophoresis; SP—selective precipitation; Lex—liquid extraction).
See this image and copyright information in PMC

References

    1. Liu J.F., Yu S.J., Yin Y.G., Chao J.B. Methods for separation, identification, characterization and quantification of silver nanoparticles. Trac Trends Anal. Chem. 2012;33:95–106. doi: 10.1016/j.trac.2011.10.010. - DOI
    1. Sajid M., Plotka-Wasylka J. Nanoparticles: Synthesis, characteristics, and applications in analytical and other sciences. Microchem. J. 2020;154:104623. doi: 10.1016/j.microc.2020.104623. - DOI
    1. Alarcon E.I., Griffith M., Udekwu K.I., editors. Silver Nanoparticle Applications. Springer; Berlin/Heidelberg, Germany: New York, NY, USA: 2015.
    1. Burdușel A.-C., Gherasim O., Grumezescu A.M., Mogoantă L., Ficai A., Andronescu E. Biomedical Applications of Silver Nanoparticles: An Up-to-Date Overview. Nanomaterials. 2018;8:681. doi: 10.3390/nano8090681. - DOI - PMC - PubMed
    1. Moeinzadeh S., Jabbari E. Nanoparticles and Their Applications. In: Bhushan B., editor. Springer Handbook of Nanotechnology. Springer; Berlin/Heidelberg, Germany: 2017. pp. 335–361.

LinkOut - more resources