Single Particle Extinction and Scattering

SPES (Single Particle Extinction and Scattering) is an cutting-edge patented technology for the characterization of subvisible/submicron particles in fluids as complex liquids and aerosols. SPES and dedicated data analysis algorithms provide more reliable and meaningful information, boosting R&D – QC processes, during lab scale design and industrial production of particles.

SPES provides more independent parameters for each single measured particle, allowing to: i) distinguish particles of different composition, ii) determine actual size distributions, iii) retrieve information about shape/aspect ratio, iv) control stability/wettability, v) monitor the presence of and characterize aggregates and vi) characterize the contaminants and process scraps in fluids.

SPES distinguishes between particles and components of complex biological, industrial or environmental fluids, including blood, urine, etc. It opens new opportunities, such as i) the characterization of particles in the context where they are supposed to operate, ii) the possibility to measure them despite the presence of synthesis residues allowing a quality control without intermediate steps, and iii) the detection and data rejection from results of possible gas bubbles.

SPES analysis can be performed in-line so to i) adjust processes parameters in real-time on the base of particles characteristics, ii) reduce process time and iii) increase synthesis yield.

How Does SPES Work in Brief?


Particles are suspended in a liquid and driven through a flow cell where a laser beam is focused. As a single particle crosses the beam, SPES records the interference pattern between the transmitted beam and the scattered light coming from the illuminated particle.


The interference pattern presents dark and bright fringes delivering the information about the optical properties of the particle: size, refractive index, internal structure, shape, payload, etc. A couple of independent, calibration-free optical parameters is retrieved, namely the Re and Im components of the forward scattered field S(0).


From a statistically meaningful number of measured particles, SPES creates the EOS CLOUDS: a 2D histograms which is the optical fingerprint of the sample. Heterogeneous systems produce simultaneously more clouds for each particle population which can be selected and analyzed separately.


Valuable information is retrieved thanks to EOS unique particle data libraries.

EOS boosts innovation through SPES! We provide standard solutions and Technology Trasnfer Services to revolutionize your products developoment, formulation and promote effective quality controls of micro and nanoparticles in biological, industrial and environmental complex fluids.