Abstract
Among different nanomaterials, gold and silver nanoparticles (AuNPs and AgNPs) have become useful tools for a wide variety of applications in general, and particularly for plasmonic assays. Particle size and stability analysis are key elements for their practical applications since the NPs properties depend on these parameters. Hence, in the present work, asymmetrical flow field flow fractionation (AF4) coupled to UV-Vis and dynamic light scattering (DLS) detectors in series, has been evaluated for stability studies of citrate-capped AuNPs and AgNPs aqueous dispersions. First, experimental parameters, such as mobile phase or cross-flow rate were optimized. Sodium azide to pH 7 for AuNPs and pH 9.2 for AgNPs were selected as the optimum mobile phase. The analytical response of bulk dispersions of AuNPs (20, 40, 60 and 80 nm) and AgNPs (20, 40 and 60 nm) and their dilutions have been studied. Fractograms showed a decrease on the absorbance signal in diluted dispersions as a function of time and particle size for the diluted dispersions that can be explained by dissolution in diluted dispersion since hydrodynamic diameter was constant. The results indicated that the dependence of the signal with time was more intense for AgNPs than for AuNPs, which can be correlated with its lower stability. These findings should be considered when plasmonic assays are realized. Here, assays involving non-oxidant acidic acids as use cases, were tested for several batches of NPs and considerations about their stability and operability stablished.
Highlights
Nanoparticles and nanotechnology have a large socio-economic impact in research and in several industrial activity areas
The results showed that RSD values were lower than 6.5%, and intraday intraday precision was suitable in aqueous diluted dispersions
We studied the kinetics of the aggregation by AF4, Figure 10 shows the fractograms corresponding to the dispersion of AgNPs in the presence of 1.5 and 3.0 mM of acetic acid at several times since its preparation
Summary
Nanoparticles and nanotechnology have a large socio-economic impact in research and in several industrial activity areas. Gold and silver nanoparticles (AuNPs and AgNPs) are used in many of the fields of science, analytical applications [1], medical applications [2], bioimaging [3], construction industry and sensor technologies [4]. Their study and characterization are necessary to fully understand and monitor their properties [5]. Different techniques have been used to characterize and quantify NPs in order to stablish their physical and chemical properties. Optical techniques and separation techniques have been proposed to supply the chemical and physical information required in different fields [6,7,8,9,10].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
