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The world’s most widely used system. It is used for the measurement of the size, electrophoretic mobility of proteins, zeta potential of colloids and nanoparticles, and optionally the measurement of protein mobility and microrheology of protein and polymer solutions. The high performance of the Zetasizer Nano ZS also enables the measurement of the molecular weight and second virial coefficient, A2, of macromolecules and kD, the DLS interaction parameter.

The system can also be used in a flow configuration to operate as a size detector for SEC or FFF.


The Zetasizer Nano ZS is a high performance two angle particle and molecular size analyzer for the enhanced detection of aggregates and measurement of small or dilute samples, and samples at very low or high concentration using dynamic light scattering with ‘NIBS’ optics. The ZSP also incorporates a zeta potential analyzer that uses electrophoretic light scattering for particles, molecules and surfaces, and a molecular weight analyzer using static light scattering.

Using Non-Invasive Backscatter optics (NIBS) it has significantly better performance than systems using 90 degree scattering optics.

In addition, a microrheology option is available for measuring sample viscosity and viscoelastic properties, as well as a Protein Measurement option for protein mobility measurements.

The flow mode option enables the system to be connected to an SEC or an FFF system to use as a detector for the size of proteins or nanoparticles.

A choice of cuvettes are available, from disposable single-use to specific cells for viscous or high concentration samples or measuring the zeta potential of surfaces.

Parameters measured:
Particle and molecule size, translational diffusion, electrophoretic mobility, zeta potential of particles at high and low concentrations, viscosity and viscoelasticity of protein and polymer solutions, concentration, MW, A2, kD.

An optional accessory enables measurement of the zeta potential of solid surfaces.

  • Size measurement from 0.3nm (diameter) to 10 microns using patented NIBS (Non-Invasive Back Scatter) technology.
  • Zeta potential using patented M3-PALS technology.
  • Molecular weight measurement down to 980Da.
  • Microrheology option to measure viscosity and viscoelasticity.
  • Protein size measurement as dilute as 0.1mg/mL (Lysozyme).
  • Sample concentrations from 0.1ppm to 40%w/v.
  • Optional protein calculators, including protein charge, A2, kD, and molecular shape.
  • A ‘Quality Factor’ and ‘Expert Advice System’ gives the confidence of having an expert at your shoulder.
  • 21CFR part 11 software option to enable compliance with ER/ES.
  • Research software option to give access to further features and analysis algorithms for the light scattering specialist.
  • Automation of measurements using an autotitrator option.
  • Optional flow mode capability to enable use as a GPC / SEC size detector.
  • Alternative laser, 50mW at 532nm for samples incompatible with the standard 633nm laser.
  • Optical filter option to improve measurements with fluorescent sample.
  • Temperature range extension option to 120ºC.

How it works

The Zetasizer Nano ZS incorporates three techniques in a single compact unit, and has a range of options and accessories to optimize and simplify the measurement of different sample types.

Dynamic Light Scattering is used to measure particle and molecule size. This technique measures the diffusion of particles moving under Brownian motion, and converts this to size and a size distribution using the Stokes-Einstein relationship. Non-Invasive Back Scatter technology (NIBS) is incorporated to give the highest sensitivity simultaneously with the highest size and concentration range.

Measurement of size as a function of concentration enables the calculation of kD, the DLS interaction parameter.

The Microrheology option uses the DLS measurement of tracer particles to probe the structure of dilute polymer and protein solutions.

Laser Doppler Micro-electrophoresis is used to measure zeta potential. An electric field is applied to a solution of molecules or a dispersion of particles, which then move with a velocity related to their zeta potential. This velocity is measured using a patented laser interferometric technique called M3-PALS (Phase analysis Light Scattering). This enables the calculation of electrophoretic mobility, and from this the zeta potential and zeta potential distribution.

A surface zeta potential accessory uses tracer particles to measure electro-osmosis close to a sample surface to calculate the zeta potential of the surface.

Static Light Scattering is used to determine the molecular weight of proteins and polymers. In this technique, the scattering intensity of a number of concentrations of the sample is measured, and used to construct a Debye plot. From this the average molecular weight and second virial coefficient can be calculated, which gives a measure of molecule solubility.

This technique is very demanding on the sensitivity and stability of the whole system, and requires that every element of the design is optimized to ensure accuracy and repeatability.

The software is designed to be versatile and rich in features without compromising ease of use. Standard Operating Procedures (SOP) simplify routine measurements, a quality factor gives a single place for confirmation of data quality, and an expert advice system is provided to assist with data interpretation.

The MPT-2 Autotitrator enables the study of the effect of changes in pH, conductivity, or any additive to be automated.

A range of disposable and reusable cells are available to optimize the measurement in terms of sample volume, concentration and flow measurement.

Other options include filters to improve the measurement of fluorescent samples, a temperature range extension to 120ºC and a viscometer to determine the sample viscosity to the accuracy required for the techniques used.


Particle size and molecular size

Measurement range:
0.3nm – 10.0 microns* (diameter).
Measurement principle:
Dynamic Light Scattering
Minimum sample volume:
Better than +/-2% on NIST traceable latex standards
Precision / Repeatability:
Better than +/-2% on NIST traceable latex standards
0.1mg/mL (Lysozyme)

Zeta potential (and optional Protein Mobility)

Measurement range:
3.8nm – 100 microns (diameter)*
Measurement principle:
Electrophoretic Light Scattering
Minimum sample volume:
150µL (20µL using diffusion barrier method)
0.12µ for aqueous systems using NIST SRM1980 standard reference material
10mg/mL (BSA).

Molecular weight

Measurement range:
980Da – 20M Da*
Measurement principle:
Static Light Scattering using Debye plot
Minimum sample volume:
12µL (3-5 sample concentrations required)
+/- 10% typical

Microrheology (option)

Measurement principle:
Dynamic Light Scattering
Minimum sample volume:
12µL (DLS measurement only) *maximum range, sample dependent


Temperature control range:
0°C - 90°C +/-0.1**, 120ºC option
Light source:
He-Ne laser 633nm, Max 4mW.
Laser safety:
Class 1
100VA ** at 25ºC

Weight and dimensions

Dimensions (W, D, H):
320mm, 600mm, 260mm (W,D,H)
21 kg

Operating environment:

10°C – 35°C
35% - 80% non-condensing


The Zetasizer Nano range is protected by the following patents: Non-Invasive Back Scatter (NIBS) EP884580, US6016195, JP11051843 High and Low Frequency Electrophoreses (M3) EP1154266, US7217350, JP04727064 Light Scattering Measurements using Simultaneous Detection EP2235501, CN102066901, JP2011523451, US20090251696 Surface Potential Determination in a Dip Cell WO2012172330


A range of accessories are available to make life easier, or to add capability to the system.


NanoSampler Automated particle size measurement for the Zetasizer Nano Image The Zetasizer NanoSampler is a sample delivery system that ensures highly precise and reproducible automated loading of samples into your Zetasizer Nano. The NanoSampler adds automation and unattended operation in a versatile, compact package, maximising the productivity of your Zetasizer Nano. While the benefits of automated operation are useful for all users, the NanoSampler is ideally suited for laboratories where a large number of measurements are required and reproducibility or multi-variate studies are important. More information
MPT-2 Simplify pH, conductivity and additive titrations on your Zetasizer Nano Image A cost effective accessory designed to automate the measurement of size and zeta potential as a function of pH, conductivity or any soluble additive. More information
SV-10 viscometer Viscosity measurement with speed, simplicity and accuracy. Image The SV-10 measures viscosity with the accuracy required for dynamic light scattering, for the conversion of diffusion speed to size, and electrophoretic mobility to zeta potential, in an extremely simple and rapid system. More information

Cell and cuvette options

Disposable folded capillary cell Eliminate sample cross contamination between zeta potential measurements using a completely disposable cell. Image The zeta potential of colloids and molecules is extremely sensitive to contamination from components of a previous sample used in a measurement cell. The use of a disposable cell completely eliminates this potential contamination issue. The folded capillary cell provides the benefits of the accuracy of measurement of a capillary cell with the ease of use of a disposable cell. Although, disposable, including the electrodes, for low conductivity samples each cell can be used for hundreds of measurements if required. The cell can be used with the autotitrator, where multiple measurements are routinely done over a wide pH range. Visit store to buy now
Universal 'dip' cell kit Reusable solvent resistant cell. Image The dip cell is used for the measurement of zeta potential of samples in aqueous and non-aqueous dispersants, and is designed to be cleaned and reused. It is for batch measurements using standard polystyrene or glass cuvettes. Visit store to buy now
High concentration zeta potential cell kit Save time and effort by measuring zeta potential with little or no dilution. Image The high concentration cell enables the measurement of the zeta potential of samples with little or no dilution in any Zetasizer Nano system that measures zeta potential. The cell has a flow configuration so can be used for stop-flow size and zeta potential measurements using an MPT-2 autotitrator as well as batch measurements. Visit store to buy now
Surface zeta potential accessory Extend the application of the Zetasizer Nano to measure the zeta potential of material surfaces. Image The characterization of surfaces and interfaces is critical in a wide range of industries including consumer products, specialty chemicals, pharmaceuticals and life sciences. In each of these application areas, the interaction of molecules and particles with surfaces can influence the material properties of the end product. The surface zeta potential accessory enables the measurement of the zeta potential of flat surfaces such as filter paper, silica, polymers and bone, using a standard Zetasizer Nano system. Visit store to buy now
Quartz flow cell (ZEN0023) Add flow capability for size measurements to the Zetasizer. Measure size and intensity with MPT-2 autotitrator. Connect to an SEC system to use as a DLS detector. Visit store to buy now
12mm Glass cell (PCS1115) Glass cuvette for use with the dip cell. For size and zeta potential measurements using the ‘dip’ cell. Compatible with aqueous and non-aqueous solvents and dispersants. Visit store to buy now
12mm Square Polystyrene Cuvettes (DTS0012) Disposable polystyrene cuvettes. 100 disposable cells complete with 100 stoppers to avoid cross contamination. For size measurements using aqueous dispersants. Compatible with zeta potential measurements using the dip cell. Visit store to buy now
12mm square glass cell (PCS8501) Glass cuvette for batch measurements. For size and molecular weight measurements. Compatible with aqueous and non-aqueous solvents and dispersants. Visit store to buy now
Disposable Solvent Resistant Micro Cuvette (ZEN0040) Disposable plastic micro cuvette, for size measurement at 173° (NIBS) optics only. 100 x 40µL cuvettes with 100 caps to avoid cross contamination. Compatible with aqueous samples and a range of other solvents: Acetone, Benzaldehyde, Butanone, Dioxane, DMF, Ethyl acetate, Isopropanol, plus various acids and bases. Visit store to buy now
Low-volume quartz batch cuvette (ZEN2112) Low-volume quartz batch cuvette for size and molecular weight measurements. Compatible with size and molecular weight measurements with aqueous and non-aqueous solvents and dispersants. Minimum sample volume 12 microliters. Maximum volume 45 microliters. Visit store to buy now
ZEN0118 Disposable low volume cuvette for size measurement with 90° optics only. 100 x 50µL cuvettes with 100 caps to avoid cross contamination. Compatible with aqueous dispersants. Visit store to buy now

Factory fitted options

50mW 532nm DPSS laser For use where the sample is incompatible with the standard 633nm laser, either because the sample absorbs or fluoresces, or the sample is photosensitive. This addition of this option does not affect the system specifications.
Narrow band filters Useful where the sample fluoresces. Eliminates scattering due to fluorescence to improve the signal to background ratio.
High temperature capability Increases the high temperature capability from 90°C to 120°C. Suitable for samples in wax media that melt above 90°C.
Degasser for MPT-2 autotitrator Titrants used by the MPT-2 titrator need regular degassing, ideally before each titration. Degassing is required to remove bubbles that can affect the volume of titrant dispensed. This is particularly important close to pH 7 where low volumes of titrant are required. The degasser is a highly recommended ‘Fit and forget’ accessory that continuously degasses titrants which improves the speed of titrations and the accuracy of reaching the target pH. This gives more evenly spaced pH points. Visit store to buy now


Protect your investment and ensure optimized performance at all times with Malvern’s service plans.

When you purchase a Malvern product we understand that this is just the first stage of a working relationship that will last for the lifetime of the instrument. Depending on your needs, Malvern will provide the support for your business.

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For laboratories where maximizing instrument up-time is critical to its daily performance. Our highest level of response and the 'all inclusive' price plan takes care of those unexpected repair bills should the unfortunate occur.


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*including labour & travel costs** Platinum 2 places per contract term, Gold 1 place per contract term***available at an additional cost


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Non-aqueous zeta potential measurements of carbon black powders Application Note (English)

The measurement of the zeta potential of non-aqueous suspensions is challenging as the electrophoretic mobility of the particles is very small. Here we describe how the Zetasizer Nano in combination with a universal dip cell accessory gives excellent...

Optimizing Small Volume DLS-Microrheology Measurements of Block Co-Polymers Used for Enhanced Oil Recovery Applications Application Note (English)

This note discusses how DLS-based optical microrheology can be used to determine the rheological behavior of polymer solutions and the impact of tracer particle chemistry on the measured microrheological response.

Suspension properties Masterclass 4: Using rheology to assess suspension stability Webinar - Recorded (English)

This presentation discusses the importance of particle size, zeta potential and rheology for a functional suspension, and demonstrates how these properties can be manipulated to induce dispersion stability.

Kinexus range,Zetasizer Nano range,Mastersizer range
Date recorded:
April 10 2013

Keywords: Suspensions, slurries and pastes English Kinexus range Mastersizer range Particle size Rheology and viscosity Zeta potential Dynamic Light Scattering Electrophoretic Light Scattering Webinar - Recorded Greenwich Time Zetasizer Nano range 

Measuring Zeta Potential - Laser Doppler Electrophoresis Explained Technical Note (English)

This technical note describes the technique used to measure zeta potential and discusses the technology used in the market leading range of Zetasizer instruments, the Nano series.

Surface zeta potential of soft, high value and fragile surfaces Poster (English)

We demonstrate the surface zeta potential measurement of pig skin, a human skin analogue used in medicine, pharmaceutical and cosmetic development and cellulose filter paper, used primarily for sterile filtration

Keywords: Surfaces and interfaces English Poster Particle size Zeta potential Dynamic Light Scattering Electrophoretic Light Scattering Cosmetics Zetasizer Nano ZS Zetasizer Nano ZSP Pharmaceutical development 
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