IMMS chip development for point-of-care devices of the medical technology industry

The earlier and more reliably cancer and heart diseases can be diagnosed, the higher the chances of successful therapies. From 2011 to 2016, one in four deaths in the EU was caused by these diseases. In this context, new and efficient methods in early detection are necessary. To advance these methods, IMMS has been working on a chip for a portable modular analysis system for quantitative personalised diagnostics of societal diseases in the joint project MEDIKIT. The goal was a point-of-care device that detects biomarkers in the shortest possible time and can be operated directly at the doctor's office without additional reagents, devices or materials. The basis was formed by the molecular biological and immunological assays for the detection of various biomarkers, on which the project partners Senova and Oncgnostics worked.

Lock-in imager for time-resolved fluorescence imaging with europium

In in-vitro diagnostics, the labeling of target analytes with fluorescent dyes is becoming increasingly common, as they can be easily distinguished from background and interfering signals. In the MEDIKIT project, IMMS has developed a lock-in imager chip for time-resolved fluorescence imaging with europium and integrated it into an example application for digital readout of test strips. Those tests, also called lateral flow assays (LFA), play an important role in in-vitro diagnostics. They are cost-effective, easy to handle and therefore perfectly suited for decentralised and time-critical diagnostics. They are widely used as pregnancy or COVID-19 rapid tests, among others, to make qualitative conclusions (positive or negative). However, quantitative information on concentrations and ratios are needed for many diagnostic questions. Common LFA reader combinations with classical dye particles such as gold are not sensitive enough for this purpose. New LFA reader combinations with europium markers offer much higher readout sensitivities, which are supported by our imager. Thanks to its lock-in principle, elaborate optical filters can be omitted.

The europium, in the demonstrator on a strip test, is optically excited by a light source and emits photons that are detected by the chip. In time-resolved fluorescence measurement, this emission is measured after the excitation light has decayed and is accumulated over several excitation cycles. In this way, even very low fluorescence can be quantitatively detected and thus higher sensitivities of the sensor can be achieved.

The modular and mobile test systems of IMMS were used and further developed for the test and characterisation of the developed lock-in imager chip.