Chemical analysis usually focuses on either the chemical composition of a molecule or its size. If you want to know both parameters, you have to combine spectroscopic analysis with other types of measurements, which require specific and often expensive instruments. ‘In addition, all instruments and methods have their limitations’, says Giulia Giubertoni, a research fellow working at the Van’t Hoff Institute for Molecular Science(HIMS), the chemistry department of the University of Amsterdam (UvA). ‘Having to perform analyses on several instruments costs time, money and wastes valuable materials.’

That’s why Giubertoni and Sander Woutersen (Professor of Physical Chemistry, HIMS, UvA) started a spin-off company to make it easier to determine the size of a molecule while taking other measurements at the same time. ‘We combined existing knowledge’, explains Giubertoni. ‘Optical spectroscopy is a well-known analytical technique and diffusion is a fundamental concept in physical chemistry, but the combination of the two into optical diffusion-ordered spectroscopy [DOSY, ed.] is the core of the innovation.’ 

Y-shaped channel

They have captured the technology in a chip that will be tailored to the needs of their future customers. ‘At the moment, we’ve almost got our prototypes, we’re validating them internally. When they are ready, we’ll take samples from companies, including pharmaceutical ones.’ One of the main advantages of the technology is that it can be simply incorporated into existing spectrometers. ‘Anyone can use our chip to turn their spectrometer into a size spectrometer, which is much easier and cheaper than for instance NMR-DOSY.’

Their current chips, IRMA and VIVA, are complementary to infrared and UV/Vis spectroscopy, respectively. They have a Y-shaped channel into which you pump the sample solution containing molecules of different sizes and pure solvent. After stopping the flow, you can perform your specific measurements. Due to the size-dependence of the diffusion coefficient, the absorption peaks of the smaller molecules will increase faster than those of the larger molecules, and the time- and frequency-dependent absorption can be converted into a two-dimensional spectrum with wavelength and size along the axes.

Giubertoni hopes that the chips will be available in the spring of 2025. ‘We are now applying for further funding and hope to be in contact with investors by the end of this year and to have our company up and running. We’re also working with another spin-off, Nano Hybrids B.V., to improve the analysis of nanoparticles with a device that looks specifically at the size of these particles; we want to go beyond just a chip.’