Five in one: physicists are on the trail of nanoparticles in liquids

Have scientifically described the technology: Christian Hill, Marko Šimić and Raphael Hauer (from left) Photo: Uni Graz/Schweiger

They are invisible to the naked eye, but sometimes painful. Even the smallest particles, which are up to 10,000 times thinner than a hair, can cause great damage in medical fluids such as eye drops. Physicists from the University of Graz and Graz University of Technology, in cooperation with the Medical University of Graz, have demonstrated which measuring methods can be used to successfully detect tiny nanoparticles. The researchers' expertise was utilised by a spin-off of the Medical University of Graz to develop the technology to market maturity.

The results of the innovative application are now available in black and white - in the form of a review article in the renowned scientific journal "Nano Letters". In it, a team of physicists from the University of Graz, Med Uni Graz and TU Graz as well as the company BRAVE Analytics summarise their five years of work. "By carrying out simulations and comparing experimental data with samples from industry, we have confirmed the functioning characterisation and analysis of nanoparticles," explains Marko Šimić from the Institute of Physics at the University of Graz.

Against production errors in cosmetics or medicines

The technology is an instrument called "Optofluidic Force Induction (OF2i)", developed by the spin-off company BRAVE Analytics. "It is more of a platform that uses sensors and five different methods to analyse liquids," explains Šimić. Together with the other authors Christian Neuper, Raphael Hauer, Karin Griesmair, Christian Hill and Ulrich Hohenester, Šimić has described how the methods work.
Co-author Hill, biophysicist and CEO of BRAVE Analytics, explains: "All sensors can be read in parallel, which enables simultaneous access to most of the data for the same particle."
Šimić adds that this allows the size, type and composition of tiny particles in the size spectrum between five nanometres and 100 micrometres to be determined in real time. These can creep into cosmetics or medicines due to production errors, for example, and then cause irritation even in very low concentrations, such as in eye sprays.
Christian Hill is convinced of the range of possible applications: "The technology can be used in areas such as infusions, medicines and vaccinations, but also in the semiconductor industry and environmental analysis."

Andreas Schweiger

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