Compact biosensors for decentralized diagnostics

Researchers at Chalmers University of Technology have developed a compact laser-based biosensor that integrates optics on a chip. The technology could enable diagnostic testing in home settings and reduce pressure on healthcare facilities. The approach combines lasers and optical components on a centimeter-sized semiconductor chip, enabling compact and potentially cost-effective diagnostic devices.

The work addresses a growing need for decentralized diagnostics in healthcare, where rapid and accessible testing can support patient monitoring and reduce the burden on clinical infrastructure.

Optical biosensors play a key role in analyzing interactions between biomolecules, such as antibodies and antigens. These interactions provide insights relevant for drug development, vaccine research and infection diagnostics.

A widely used method is surface-plasmon resonance (SPR). In this technique, light is directed onto a gold surface, and small changes in reflected light are measured when biomolecules bind to the surface. This allows highly sensitive detection of biological processes in real time.

The Chalmers research team has developed a new approach that integrates both the laser source and optical components directly into a semiconductor chip. This eliminates the need for bulky external components such as prisms, which are typically required in conventional SPR systems.

The resulting chip measures around one centimeter and contains hundreds of microscopic lasers. Each laser is approximately 200 × 250 micrometers in size. By embedding the optics within the chip, the system can generate the precise light beam required for biomolecular sensing in a significantly more compact format.

The technology could support a range of diagnostic applications outside traditional laboratory environments. One example currently under evaluation is the measurement of C-reactive protein (CRP), a biomarker commonly used to detect inflammation.

"With this technology, we want to create an instrument that allows healthcare professionals to take certain samples in the patient’s home. For example, we’re currently evaluating how well our sensor can perform a C-reactive protein (CRP) test. Because this technology is very general and can detect a wide range of biomolecular interactions, we see many potential applications for a wide variety of tests. This could allow patients to be discharged from hospital sooner after an operation – thereby freeing up hospital beds – and reduce the number of healthcare visits for sampling," says Erik Strandberg, doctoral candidate in photonics at Chalmers and lead author of the study published in ACS Sensors.

Potential benefits include:

• reduced hospital stays and fewer clinic visits
• improved access to diagnostic testing
• support for remote patient monitoring

The researchers are now focusing on improving the sensitivity of the biosensor and increasing the number of samples that can be analyzed simultaneously.

"So far, we haven’t been able to use all the lasers on our chips to analyze samples, but this field offers great opportunities for further development. If we succeed, we believe the sensor will eventually make it possible to analyze significantly more samples at once than current technologies allow. But first, we plan to create a prototype of a portable sensor that can be used without extensive training. The ultimate goal is for hospitals and clinics to be able to use the sensor outside the lab," says Hana Jungová, senior researcher in the study.

The development highlights ongoing efforts to translate optical sensing technologies into practical tools for clinical and home-based diagnostics.

MEDICA-tradefair.com; Source: Chalmers University of Technology