UCL Centre for Nature Inspired Engineering


NanoBrook Omni Dynamic Light Scattering (DLS) Particle Sizer and zeta petential Analyzer (Brookhaven

The NanoBrook Omni particle sizer and zeta potential analyzer offers users with fast, routine, sub-micron measurements of size and zeta potential for proteins, polymers and colloidal dispersions.


Based on the principles of Dynamic Light Scattering (DLS) for particle sizing and distribution, and on Doppler velocimetry (electrophoretic light scattering, ELS) for zeta potential, most measurements only take a minute or two. The instrument also includes Phase Analysis Light Scattering (PALS) measurements for samples with low mobilities (saline, PBS). 


 Rapid and accurate nanoparticle size distributions

• Range: > 0.3 nm to 10 μm

 • Three measurement angles: 15°, 90°, & 173°

 • High power 35 mW diode laser

• Dynamic light scattering at 173° and 90°

 • Temperature control, -5 °C to 110 °C

 • Molecular weight determination 


• For proteins, peptides, mAb, RNA, and other biological samples

• For zeta potential in organic solvents

• For oily or viscous media

• For high-salt suspensions

• For samples near the I.E.P.

• 1,000 times more sensitive than other techniques

• Disposable cuvettes, no contamniation or alignmnent

• Built in automatic procedures and parameters (SOP)

Scattering Angles

Measurements of traditional colloids are usually made at 90° scattering angle due to the unbiased results measured. For nanoparticles and proteins, IgG and peptides, these < 50 nm samples can be measured using the backscattering angle (173°) for best S/N and reproducibility of measurements. The 15° detection angle can be selected for added sensitivity with aggregation measurements. Zeta potential measurements are always performed using the 15° detection angle to minimize diffusion broadening.

Principles of Operation - Sizing

Dilute suspensions, on the order of 0.0001 to 1.0% v/v are prepared, using suitable wetting and/or dispersing agents, if required. A small ultrasonicator is sometimes useful in breaking up loosely-held agglomerates. At 173 sample volume may be reduced to 50 μL with a polystyrene, U-shaped, disposable cuvette and the sample is recoverable. At 90° square polystyrene or glass cells (two or three mL) are used, one as small as 10 μL (non-disposable). In addition, disposable, glass round cells with reusable Teflon stoppers are used for aggressive solvent suspensions. In all case, just a few minutes are required for the sample and cell to equilibrate with the actively controlled temperature environment inside the NanoBrook Omni.

Principles of Operation - Zeta Potential

The NanoBrook Omni utilizes phase analysis light scattering to determine the electrophoretic mobility of charged, colloidal suspensions. Unlike its cousin, Laser Doppler Velocimetry (LDV, [sometimes called Laser Doppler Electrophoresis, LDE]), the PALS technique does not require the application of large fields which may result in thermal problems or denaturation, because in the measurement of phase shift, the particles need only to move a fraction of their own diameter to yield good results. In salt concentrations up to 2 molar and with electric fields as small as 1 or 2 V/cm enough movement is induced to get excellent results. In addition, the Autotracking feature compensates for thermal drift.


Sample Type

Sizing: nano particle and colloidal-sized materials, in any non-absorbing liquid. Zeta potential: proteins, nano particle, polymer and colloidal-sized materials, suspended in any non-absorb­ing liquid, with relative permittivity (dielectric constant) > 1.5 and viscosity < 30cP.

Size Range             Nano particle and colloidal-sized materials, in any non-absorbing liquid

Mobility Range

10-11 to 10-7 m2 /V*s

Zeta potential range

-500 mV to 500 mV, sample dependent

Maximum sample conductivity

Sizing: unlimited

Zeta potential: 30 mS/cm

Sample Cells

Sizing: 1 to 3 mL disposable plastic, 50 μL disposable, 40 μL quartz flow cell, 10 μL quartz minimum

Zeta potential: 180 μL, 600 μL, 1250 μL

Concentration Range

Sizing: 0.1 ppm to 50 mg/mL, depending on refractive index and concentration

Zeta potential: 40% v/v, sample dependent

Signal Processing

Sizing: Dynamic Light Scattering, DLS

Zeta potential: Electrophoretic & true Phase Analysis Light Scattering, ELS & PALS


Brookhaven’s TurboCorr, multitau, research grade with 510 channels, covering the equivalent of 1010 linearly-spaced channels, 100% efficiency, real-time operation over the entire delay-time range.


Sizing: ± 1% typical

Zeta potential: plus minus 3% typical

Data Presentation

Average & width, lognormal fit, and multimodal size distribution for sizing Doppler Frequency Shift, electro­phoretic mobility, zeta potential using Smoluchowski, Hückel, or Henry


ISO13321 and ISO22412 compliant results for sizing

Power Requirements

100/115/220/240 VAC, 50/60 Hz, 150 Watts


23.3 x 42.7 x 48.1 cm (HWD)


15 kg

Environmental Characteristics

Temperature 10 ° C to 75 ° C

Humidity 0% to 95%, non-condensing

CE Certificate

Class I laser product, EN 60825-1:2001, CDRH