NanoBrook Series

Characterizing proteins, nanoparticles, & polymers confronts users with a difficult choice of instrumentation. Brookhaven Instruments makes that choice easier with its highly configurable NanoBrook series of products.


The NanoBrook Series is a Configurable Platform for Particle Sizing and Zeta Potential Measurements

The NanoBrook Series size and zeta potential analyzers incorporate all you need for fast, routine, sub-micron measurements of size and zeta potential. Based on the principles of Dynamic Light Scattering (DLS) for particle sizing and distribution, and based on doppler velocimetry (electrophoretic light scattering or ELS) for zeta potential measurement, most measurements only take a minute or two. The instrument also includes Phase Analysis Light Scattering (PALS) measurements for samples with low mobilities.

The NanoBrook Omni combines all of the most common configurations

With the NanoBrook Omni, measure samples in nearly every possible suspension environment from high salts such as PBS and sea water to organic solvents and aqueous solutions. Particle and protein sizing, with the highest sensitivity, utilizing three measurement angles for truly unbiased measurement results.

Features at a glance


  • Rapid and accurate protein & nanoparticle size distributions
  • Multimodal & unimodal size distribution software
  • ISO 13321 and ISO 22412 compliant results
  • Range: < 0.3 nm to 10 µm
  • Three measurement angles: 15°, 90°, and 173°
  • Ideal for fast, routine sizing applications in research or quality control
  • High power 40 mW diode laser
  • Dynamic light scattering at 173° and 90°
  • Temperature control, -5 °C to 110 °C
  • Compact bench top unit, USB connection
  • Molecular weight determination (relative and absolute through Debye plot)


  • Zeta potential for the difficult cases
  • 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 contamination or alignment
  • Built in automatic procedures and parameters (SOP)
  • Easy to use

Measurement Principles

Rapid, Reliable, and Accurate Analysis

The NanoBrook Series particle size and zeta potential analyzers are based on the principles of Dynamic Light Scattering (DLS) for particle sizing and distribution, and based on doppler velocimetry (electrophoretic light scattering, ELS) for zeta potential measurement. Most measurements only take a minute or two. These instruments can also be configured with Phase Analysis Light Scattering (PALS) for samples with low mobilities or high conductivity measurements.

Three Possible Scattering Angles

Measurements of colloids are traditionally made using a 90° scattering angle. For smaller nanoparticles, proteins including IgG, mAbs, and peptides, these < 50 nm samples can be measured using the backscattering angle (173°). Finally 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.

Data Presentation

image of DLS report
Figure 1

The NanoBrook particle size and zeta potential analyzer offers three choices. For routine determinations an average diameter (Eff. Dia.) and a measure of the distribution width (Polydispersity) are sufficient for many applications. This is illustrated above in Figure1 for the latex with a narrow size distribution. The second choice is to fit these values to a lognormal distribution, allowing the user to visualize the size distribution and to interpolate cumulative and differential results at 5% intervals.

image of bimodal test resultsFigure 2: Results from Test Bimodal Sample on NanoBrook Omni (diameters, in nm)

Figure 2 above shows an example of the third choice, suitable for more complicated, multimodal size distributions. Here, a numerical algorithm, including Mie theory, is used. These results are for a mixture of known latex particles. Positions of the measured particle sizes on the accompanying graph are in excellent agreement with the known sizes of 92 and 269 nm.

During a measurement, the display can be switched interactively between any one of these — correlation function, lognormal, or multimodal — each shown “live” as data are accumulated. The live display is particularly useful in determining the end-point of a measurement where multimodal distribution shape may be important

Phase Analysis Light Scattering

For measurements of very low mobilities, the Brookhaven NanoBrook is the answer; the only answer! With concepts developed at Bristol University and Brookhaven Instruments, the NanoBrook determines zeta potential using phase analysis light scattering: A technique that is up to 1,000 times more sensitive than traditional light scattering methods based on the shifted frequency spectrum.

Electrostatic repulsion of colloidal particles is often the key to understanding the stability of any dispersion. A simple, easy measurement of the electrophoretic mobility “even in nonpolar liquids” yields valuable information. Measurements made in water and other polar liquids are easy and fast with the NanoBrook. Such measurements cover the range of typically ± (6 to 100) mV, corresponding to mobilities of ± 0.5-8×10-8 m2 /Vs. The NanoBrook covers this full range, of course, and extends it by a factor of 1000 in sensitivity!

Principles of Operation – Zeta Potential

The NanoBrook 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. This is due to the fact that the measurement analyzes the 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.

image of test resultsFigure 3

Simple and clear presentation

Figure 3 above shows the results of an actual experiment with a NanoBrook instrument. The important parameters and results are seen at a glance. The excellent agreement of the five runs in this experiment is obvious as is the match of experimental curve (red, bold) and it’s fitted version (red, thin). As with all Brookhaven instruments the user can simply produce a customized report.

Custom Columns

The software can be easily customized to display the columns needed for a quick review of the important parameters as shown below.

image of custom columns

Comprehensive Information – ELS

The NanoBrook measures complete electrophoretic mobility distributions in seconds including multimodals. An example of bimodal zeta potential sample can be seen on the result screen from analyzing a created mixture of charged particles.

In Figure 4 below the results of analyzing a mixture of alpha and gamma Aluminas in 1 mMolar KCI at pH10 is displayed. The left peak is identified with the green cursor and shown to have a zeta potential of -20.54 mV. If the other peak is chosen the value given is -5.00 mV. The ability of the NanoBrook to provide this information distinguishes it from other methods which provide only an ensemble average.

image of results of analyzing a mixture of alpha and gamma Aluminas in 1 mMolar KCI at pH10
Figure 4

Something more challenging – PALS

Of course the NanoBrook can quickly and easily yield results from all “regular” samples but its real strength is in the difficult cases and to demonstrate the performance of this premium instrument where others fail, we offer the follow table.

Multiple Sample Types

Table 1 below shows a variety of difficult to measure samples, all of which were easily measured with the NanoBrook. Some were measured in high salt concentration; some in low dielectric constant non-polar solvents; and one in a viscous liquid.

Electrophoretic Mobilities Determined with the NanoBrook Omni
(units 10-8 m2 /V·s)
Sample PALS Result Lit. Value Comments
NIST 1980 2.51 ± 0.11 2.53 ± 0.12 Electrophoretic mobility standard.
Blood Cells -1.081 ± 0.015 -1.08 ± 0.02 Dispersed in physiological saline
Fe2O3 0.013 ± 0.0015 N.A. Dispersed in dodecane
TiO2 0.255 ± 0.010 N.A. Dispersed in toluene – not dried
TiO2 0.155 ± 0.011 N.A. Dispersed in toluene – dried
TiO2 -0.503 ± 0.0015 N.A. Dispersed in ethanol
Casein -0.025 ± 0.002 N.A. Dispersed in PEG – viscous
SiO2 -0.73 ± 0.04 N.A. Dispersed in 2.0 M KCl – High salt

Biological samples such as proteins, antibodies, peptides, DNA/RNA are easily denatured by electrical fields. Brookhaven’s NanoBrook can successfully measure the mobility of biological samples with typical voltages from 2 to 4 Volts. In Figure 3 above, Lysozyme was measured with 2.5 volts applied.

Aggressive solvents such as DMF, THF, DMSO, MEK, etc., are easily accommodated by the Brookhaven NanoBrook system with the use of our special solvent resistant electrodes and glass sample cells. The extension of zeta potential measurements in the realm of such systems is just another standout property of the Brookhaven NanoBrook.

Usual solvent? If your solvent is unusual then its dielectric constant is probably unknown. In this case our BI-870 Dielectric Constant Meter will quickly and accurately provide the information necessary for a zeta potential measurement.

Surface Zeta Potential – Principles of Operation

The Surface Zeta Potential feature allows the user to measure the electrical charge on materials like coated glass, plastic, tape, or other flexible surfaces. A series of measurements are taken on probe particles at different distances from a surface and the Surface Zeta Potential is calculated as shown:

image of surface zeta potential


Simple fluids like water (low viscosity), glycerin (high viscosity) are Newtonian and exhibit viscosity effects, the dissipation of energy when particles move in such fluids. But dissolve macromolecules in these liquids –synthetic or biopolymers—and networks can form. In addition to viscosity effects, there are now elasticity effects, the storage of energy when embedded particle move. By following the mean square displacement (MSD) of tracer (probe) particles in such fluid and microrheological properties such as η*, the complex viscosity, G″, the viscous loss modulus, and G′, the elastic storage modulus, can be determined as a function of frequency.

Measurement of the autocorrelation function (ACF) using DLS techniques yields the MSD of tracer particles, which, under the right conditions, can be used to determine η*, G″, and G′ over a range of frequencies much higher than mechanical rheometers can attain. Much smaller sample volumes, in the microliters, are possible compared to mechanical instruments. Finally, since strains result from the thermally driven motion of tracer particles, these much smaller strains allow the study of fragile samples. The study of viscoelasticity in aggregating dilute protein solutions is a prime example of the benefits of DLS microrheology.

Typical Applications

  • Proteins, IgG, peptides, RNA/DNA
  • Liposomes, exosomes, and other biocolloids
  • Polysaccharides
  • Nanoparticles
  • Polymer latexes
  • Pharmaceutical preparations
  • Micelles
  • Oil/Water and Water/Oil emulsions
  • Paints and pigments
  • Colloids
  • Polymers
  • Pigments, inks and toners
  • Cosmetic Formulation
  • Ceramics and refractories
  • Emulsions (foodstuffs, cosmetics)
  • Wastewater treatment monitoring
  • Carbon blacks


Sample Type Sizing: Globular proteins, nanoparticles, and small polymers  as well as most colloidal-sized materials in any non-absorbing liquid

Zeta Potential: Proteins, nanoparticle, polymer and colloidal-sized materials, suspended in any non-absorbing liquid, with relative permittivity (dielectric constant) > 1.5 and viscosity < 30 cP.

Size Range Sizing:  > 0.3 nm to 10 µm diameter, depending on refractive index and concentration

Zeta potential: 1 nm to 100 µm, sample dependent

Mobility range 10-11 to 10-7 m2/Vs
Zeta potential range -500 mV to 500 mV, sample dependent
Maximum sample conductivity Sizing: unlimited

Zeta potential: 220 mS/cm, covering saline and PBS solutions for proteins, sample dependent

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

Correlator Brookhaven’s TurboCorr, multitau research grade with 510 hardware channels, covering the equivalent of 1010 linearly-spaced channels, 100% efficiency, real-time operation over the entire delay-time range
Precision Sizing:  ± 1% typical

Zeta Potential: ± 3% typical

Temperature Control -5 °C to 110 °C, ± 0.1 °C, active control. No external circulator required.
Condensation Control Purge facility using dry air, nitrogen preferred
Standard Laser 40 mW red diode laser, nominal 640 nm wavelength
Available Scattering Angles 15°, 90°, and 173°
Data Presentation Average & width, lognormal fit, and multimodal size distribution standard.

Doppler Frequency Shift, electrophoretic mobility, zeta potential using Smoluchowski, Hückel or Henry.

Compliance ISO 13321 and ISO 22412 compliant results
Power Requirements 100/115/220/240 VAC, 50/60 Hz, 150 Watts
Dimensions 23.3 x 42.7 x 48.1 (HWD in cm)
Weight 15 kg
Environmental Characterisitics Temperature 10 °C to 75 °C
Humidity 0% to 95%, non-condensing
CE Certificate Class I laser product, EN 60825-1:2001 CDRH

A policy of continual improvement may lead to specification changes.

Options & Accessories

Options for particle sizing

90PDP Absolute molecular weights of polymers in solution. Option includes 40 µL flow cell (90PFC) and Debye plot software. Relative molecular weight calculated from the DLS determination of the diffusion coefficient is standard.
BI-PSD21 21 CFR Part 11 software to assist ERES compliance, sizing only.
BI-IQOQPQ Qualification for installation, operation and performance for sizing and zeta.
BI-SFS Sample filtration system provides fast and convenient way to clean your light scattering samples, a necessity for samples smaller than 20nm. Utilizing Teflon® tubing and nonreactive components, the BI-SFS is compatible with most sample filtration needs provided there is at least 5 mL of liquid. For protein and other rare samples, use 20 nm BI-DF20AQ Anatop filters instead.
Lasers Additional options available; contact us for more information.

Accessories for particle sizing

 Cells BI-SCP Box of 100 plastic cells with caps, 2.2 to 4.5 mL volume. Use with water, for sizing and zeta.
BI-SM50 Box of 80 plastic cells, disposable, 50 µL volume, sample retrievable, requires BI-SM50A. Use with water.
BI-SM50A One sample cell adaptor for use with BI-SM50.
BI-SM10 One 10 µL cell for sizing of small and rare samples, sample is retrievable.
90PFC Additional 40 µL quartz flow cell for use with 90PDP
Reference Materials BI-LTX92 Latex reference material for validation for sizing, 15 mL, 92 ± 3 nm.
BI-SVK92 Starter validation kit for sizing, 2 mL, 92 ± 3 nm.
BI-CC Nitrogen-purge facility for condenstation control.

Options for zeta potential

BI-ZTU Autotitrator, 4-pump, pH, temp, conductance for use with acids, bases, surfactants, dispersing agents, salts and other additives to determine the IEP and trend of zeta potential with concentration of additive. BI-ZTU includes one BI-ZELF and one BI-ZELF-B for use with aqueous samples.
BI-ZELF Plastic electrode assembly for use with BI-ZTU in flow mode, including one BI-ZELF-B, for use in water.
BI-ZELF-B Box of 2 plastic flow cells for use with BI-ZELF. Use in aqueous environments.
BI-870 Dielectric constant meter improves accuracy when calculating zeta potential in solvent mixtures and speciality solvents.
BI-PALS21 21 CFR Part 11 software to assist ERES compliance.

Accessories for zeta potential

BI-SREL Solvent resistant electrode assembly for use with BI-SCGO glass cells, inconvenient for use with BI-SCP cells.
BI-SCGO Box of 10, open-topped glass cells for use with solvents.
BI-SVE175 Electrode assembly for aqueous systems, with BI-SCP cell, 175 µL sample volume.
BI-ELECCK Electrode cleaning kit including wand and polishing strip, for use with BI-ZEL and BI-SREL.
BI-ZR5 Zeta reference material for validation, blue pigment for use in water, – (44 ± 8) mV.

Note: Current users of the 90Plus PALS may upgrade to include backscatter provided their instrument has the necessary mechanics, optics and hardware. Contact us for more information.

Download Brochures

NanoBrook Family brochures

NanoBrook Omni

NanoBrook Omni Brochure PDF

Other Possible NanoBrook Configurations

NanoBrook 173 Brochure PDF

NanoBrook 90Plus Brochure PDF

NanoBrook 90Plus PALS Brochure PDF

NanoBrook ZetaPALS Brochure PDF

NanoBrook ZetaPlus Brochure PDF

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