WHY THIS MATTERS IN BRIEF

As we develop more nanoscale things we need to be able to keep track of them and monitor them and now we have an inexpensive way to achieve that.

Researchers from ITMO University in Russia have created a new type of optical Nano-Sensor that can be used to rapidly detect and diagnose disease that can be quickly made using nothing more that a common inkjet printer, just like the one you likely have at home, and some special ink made from Titanium Oxide, and the secret behind their breakthrough is based on how light interacts with thin films – an effect that can be observed when you look at a common a garden soap bubble. The results are published in Nanoscale.

Today the design of sensitive and inexpensive sensors for biomedical research is one of the biggest challenges in modern science, and to solve it the team changed how their inkjet printer worked to print a new type of nanoscale substrate, or material, that can detect nanoscale objects that are incredibly small, and the process started after the team had prepared a special ink containing Titanium Dioxide. Using their printer they then applied this ink to a silicon substrate in the form of a film that was 200 to 400 nanometers thick, which is hundreds of times thinner than a human hair. Due to this interference the transparent film appears to be coloured, and its colour depends on its thickness. Once a nano-scale object, be it a nanoparticle or a bacteria, is attached to the films surface, the thickness changes and so does the colour, and using a specially designed scale for the film colour assessment, the team were able to figure out how many nano-objects were on the surface and what size they are. The sensor prototype is also capable of conducting both qualitative and quantitative analysis, although apparently it’s not yet selective, and the researchers eventually plan on immobilising antibodies on the film’s surface to detect the individual proteins in biological samples.

“We did a lot of preparation: designed the concept and studied a lot of literature. Since this method is based on a complex physical phenomenon, we not only worked as chemists, but also attempted to take into account the optical, technological and biological aspects. This way, we managed to solve a number of technical issues during the experiment: we selected the parameters of the film and the substrate and also adapted the previously developed ink. Our further work is aimed at adapting the developed system for the biomedical application of such sensors,” comments Anna Frosinyuk, the first author of the study and a student at ITMO University’s SCAMT Laboratory.