Particle Sizing Suite
Particle size is often one of the most critical physical parameters to any small molecule or particulate system. Particle sizing is therefore routinely carried out in a broad spectrum of industries, as it enables an understanding or prediction of the down stream behaviours of the final product.
In particular the variants and modalities of electron microscopy are all applicable on a significantly variable size range and population distributions. For example, TEM imaging is typically used to characterise nanoscale features and has little capacity to look at larger features. Equally core SEM imaging typically looks at the micro-scale and cannot be used for nanoscale feature imaging without discreet selection of technical variants.
As such in samples where there is little other characteristic data available it can be hugely beneficial to pre-screen the sample via a particle sizing technique to determine which EM mode will be the most appropriate, or indeed rule one out.
The nmRC is therefore home to a series of particle sizing infrastructure designed to support research needs and supplement the other physical and chemical analyses at the centre.
nmRC Particle Sizing Instrumentation
Malvern Zetasizer Nano-ZS
Dyanmic Light Scattering (DLS)
- Determination of the size of nanoscale and microscale particles.
- Uses the fluctuations in the intensity of light scattered from dispersed particulates as they move under Brownian motion to calculate a hydrodynamic radius.
- Measurement: 0.3-10,000 nm.
- Minimum sample volume of 12 microlitres.
- Accuracy: >±2% relative to NIST latex standards.
- Sensitivity: 0.1mg/ml (Lysoyme).
- Temperature Range: 0-90 (±0.1) oC.
Electrophoretic Light Scattering (ELS)
- Used to determine the surface charge of nanoscale and microscale particles.
- Measures the electrophoretic mobility of a dispersion of particles under an applied electric field using a patented laser interferometric called M3-PALS. This is then related by the Henry equation to give the Zeta Potential (surface charge).
- Measurement: 3.8-100,000 nm.
- Minimum sample volume of 150 microlitres.
- Accuracy: 0.12um.cm/V.s relative to NIST standards.
- Sensitivity: 10mg/ml (BSA).
Malvern Nanosight LM10 and LM14
Nanoparticle Tracking Analysis (NTA)
- Used for the determination of the size of nano- and micro-scale particulates.
- The Nanosight systems pass a laser beam through the sample chamber, where the particles in suspension in the path of the beam scatter light that is visualised by a 20x magnification video microscope. Sequential (30 frames p/second) files of the scattered light can then be analysed and using the Stokes-Einstein equation a hydrodynamic radius calculated.
- Measurement: 10-2,000 nm
- Concentration: 106-109 particles/ml
- Operable in conventional scattering and fluorescence tracking modes