Techniques For Accurate Sizing Of Gold Nanoparticles Using Dynamic Light Scattering With Particular Application To Chemical And Biological Sensing Based On Aggregate Formation

Keywords

biosensing; chemical sensing; dynamic light scattering; gold nanoparticle; particle sizing

Abstract

Gold nanoparticles (AuNPs) have found broad applications in chemical and biological sensing, catalysis, biomolecular imaging, in vitro diagnostics, cancer therapy, and many other areas. Dynamic light scattering (DLS) is an analytical tool used routinely for nanoparticle size measurement and analysis. Due to its relatively low cost and ease of operation in comparison to other more sophisticated techniques, DLS is the primary choice of instrumentation for analyzing the size and size distribution of nanoparticle suspensions. However, many DLS users are unfamiliar with the principles behind the DLS measurement and are unware of some of the intrinsic limitations as well as the unique capabilities of this technique. The lack of sufficient understanding of DLS often leads to inappropriate experimental design and misinterpretation of the data. In this study, we performed DLS analyses on a series of citrate-stabilized AuNPs with diameters ranging from 10 to 100 nm. Our study shows that the measured hydrodynamic diameters of the AuNPs can vary significantly with concentration and incident laser power. The scattered light intensity of the AuNPs has a nearly sixth order power law increase with diameter, and the enormous scattered light intensity of AuNPs with diameters around or exceeding 80 nm causes a substantial multiple scattering effect in conventional DLS instruments. The effect leads to significant errors in the reported average hydrodynamic diameter of the AuNPs when the measurements are analyzed in the conventional way, without accounting for the multiple scattering. We present here some useful methods to obtain the accurate hydrodynamic size of the AuNPs using DLS. We also demonstrate and explain an extremely powerful aspect of DLS - its exceptional sensitivity in detecting gold nanoparticle aggregate formation, and the use of this unique capability for chemical and biological sensing applications.

Publication Date

8-24-2016

Publication Title

ACS Applied Materials and Interfaces

Volume

8

Issue

33

Number of Pages

21585-21594

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1021/acsami.6b06903

Socpus ID

84983542324 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84983542324

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