IG-1000

To a single nanoparticle region

IG-1000 won the Bronze Award for "Writer" at Pittcon2009 IG-1000 single nanometer particle size measurement device: goes beyond the single nanometer region and penetrates into the sub nanometer region. This instrument adopts the induced grating (IG) method, which is a novel approach based on the use of two-dimensional electrophoresis and diffraction phenomena to measure particle size in the nanometer range.

For the measurement of nanoparticles, the conventional method uses dynamic light scattering, but for particles smaller than 100 nanometers, the light will be dispersed and the intensity will sharply decrease. In addition, in the single nanometer particle size range (e.g. particle size less than 10 nanometers), physical limitations make it difficult to detect scattered light, making particle size measurement also challenging. The IG method does not use scattered light, so it is not physically limited and does not require input refractive index as a measurement condition. Therefore, it makes the measurement of nanoparticles simple and highly sensitive, especially effective for the analysis of single nanoparticle particles.

High sensitivity analysis of single nanoparticles

Induced grating technology uses diffraction gratings formed by particles to emit diffracted light, rather than scattered light emitted by particles. Therefore, even in a single nanoparticle region, sufficient signal-to-noise ratio, good repeatability, and stable measurement can be obtained.

pollution-resistant

The new measurement principle is resistant to pollution, and even if the sample is mixed with a small amount of foreign matter, the particle information to be analyzed should be reliable and effective. This means that sample filtration aimed at removing coarse particles is not necessary.

High reproducibility

Stable data. Especially for particles with a particle size less than 10 nm, they have high repeatability, avoiding the uncertainty and ambiguity of particle analysis in the single nanoparticle region. At the same time, the raw data of diffracted light can be used for comparison between measurements, which can easily verify the measurement results.

What is the "induced grating method"?

The change in refractive index of nanoparticles in a medium is influenced by their concentration. Therefore, if particles are subjected to external forces to form a periodic concentration distribution in the medium, forming a grating like shape, it will act as a diffraction grating. If external forces are removed, the grating will also disappear as the particles disperse. Specifically, the IG method measures the particle size by measuring the intensity and time of the change in diffraction light intensity caused by the gradual disappearance of diffraction gratings formed by particle aggregation after external force is applied.

Diffraction grating of particles formed by two-dimensional electrophoresis

Alternating voltage is applied to periodically arranged electrodes, and under the action of an electric field, particles electrophorese in the liquid and form a periodic concentration distribution. The aggregated particles form a diffraction grating. Although the periodic concentration distribution of particles acts as a diffraction grating (particle concentration grating), if the alternating voltage is stopped, the particles will freely diffuse and the grating will disappear (in the patent application).

Key points of IG method

Unique electrode design enables accurate measurement

The periodically arranged electrodes themselves also serve as a diffraction grating. The diffraction light generated by the electrode diffraction grating is weaker than that generated by the particle concentration diffraction grating. In order to accurately measure the changes in the main diffraction light caused by the diffusion of particle concentration diffraction light, it is necessary to ensure that the positions of the diffraction light generated by the two diffraction gratings do not overlap. To achieve this goal, the electrode design is modified as shown in the figure so that the spacing between the electrode diffraction gratings is half of the particle concentration grating (in the patent application).