Gold nanoparticles: Size matters, and so does stability

Gold nanoparticles are now used in many fields, from medicine to electronics, but each application has specific particle-size and stability requirements. Gold nanoparticles can be easily monitored with the Litesizer™ 500.

Gold nanoparticles - why the particle size is important

Gold nanoparticles are promising materials for drug delivery because they are relatively stable and non-toxic, but they also have unique electronic and optical properties, which allow them to be monitored and controlled.

Many of the useful properties of gold nanoparticles depend on their particle size. In drug delivery, for example, the particles must be small enough to be transported through the body’s vessels, and across certain cell membranes. Therefore, it is important to monitor particle size to ensure that the particles will be effective in their application.

Particle stability is also an issue: under some conditions, gold nanoparticles can form aggregates, which will lead to a much greater effective particle size, and a possible loss of effectiveness. Thus, monitoring colloidal stability is also important for many applications.

How Anton Paar can reveal particle size and stability

Gold nanoparticle size and stability can be measured easily and accurately with the Litesizer™ 500, even in highly dilute or less stable colloids.

The Litesizer™ 500 measures particle size, zeta potential and molecular mass by light-scattering technology with ingeniously simple software.

The real particle size: Gold nanoparticles are often provided as dry samples. Their hydrodynamic radius in a colloid may be much greater than the quoted dry radius. The actual size of the nanoparticles, as well as their tendency to settle (where they are no longer dispersed) and/or form aggregates, can be easily monitored with time, temperature, pH or concentration.

Patented technology—cmPALS—is at the heart of the Litesizer™ 500’s state-of-the-art zeta potential measurements. This technology results in higher-accuracy and shorter measurements, which are of vital importance for highly dilute or less stable colloids.

Learn more about the Litesizer™ 500

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Good to know

The Litesizer™ 500 measures transmittance continuously, which provides a direct measure of turbidity. It also allows automatic adjustment of parameters; eg, focus and attenuation.