Nanosight

Manufacturer

Nanosight

Belonging Categories

Nanoparticle measurement equipment

Application Fields

Nanoparticle Tracking Analysis

NanoSight has developed a unique capability to directly size and visualize nanoscale particles in liquids, with high-resolution, in real-time and with minimal sample preparation. Nanoparticle Tracking Analysis (NTA) is a nanoparticle visualization technique that provides size, count and concentration measurements. NTA delivers an unprecedented insight into true size distributions, even when the systems are complex and polydisperse, and supports the exclusive numerical data with corroborating images.

High-Resolution Size Analysis of Complex Dispersions

NanoSight instruments use a laser light source to illuminate nanoscale particles. Enhanced by a near-perfect black background, the particles appear individually as point-scatters moving under Brownian motion. Polydisperse and multimodal systems are instantly recognizable and quatifiable. Fluorescence mode can be used to discriminate particles from non-labeled background. The NTA image analysis software automatically tracks and sizes many particles simultaneously. Results are displayed as frequency size distributions and output to spreadsheet. Supplementary scatter intensity data is combined with these size distributions to provide 3D plots which highlight disparate populations. Video clips of images are recorded and retained for further analysis.

Capabilities of NTA Measurements

• Direct and live view of particles in suspension
• Particle-by-particle, high-resolution particle sizing
• Especially applicable to polydisperse systems
• Measurement of concentration and particle count
• Scattering intensity distribution
• Evidence of non-sphericity and of aspect ratio
• Sizing down to 10nm, material dependent
• Number vs. intensity vs. size is provided for each particle size class

The direct observation of particle motion and scattering behaviour provides a wealth of additional information beyond particle size. These real-time observations validate the reported particle size distributions and provide instant insight into polydispersity and state of aggregation. Measurements take just minutes allowing time-based changes and aggregation kinetics to be quantified.

Comparison to Traditional Methods

NTA is not DLS/PCS (Dynamic Light Scattering/Photon Correlation Spectroscopy), although both are informed by Brownian motion. Whilst DLS measures change in scatter intensity of the bulk sample, NTA measures observed particle diffusion directly, particle-by-particle. Consequently NTA has these features:

• Overcomes intensity-biased results seen in DLS/PCS
• Size is calculated particle-by-particle
• Provides high-resolution measurement of distribution
• Direct measurement without modelling or assumptions
• An absolute method not requiring calibration
• Immune to interference from dirt and aggregates
• Requires no information about collection angle, wavelength or solvent refractive index
• Minimal sample preparation, with automation capability

NanoSight measures the diffusion coefficients of individual particles and builds the distribution one particle at a time. This compares favourably with an ensemble measurement of the combined light scattering intensity of a population of particles. Consequently, rather than presenting an ideal curve driven by a range of assumptions, NanoSight's results are a true high-resolution particle size distribution. This methodology is especially strong in characterizing complex and polydisperse systems.