London: Researchers have developed a self-contained fibre optic sensor for smartphones that can be used in a wide variety of biomolecular tests, including those for detecting pregnancy or monitoring diabetes.
The readings of the sensor can run through an application on a smartphone which provide real-time results.
"When properly provisioned, the smartphone-user has the ability to monitor multiple types of body fluids, including: blood, urine, saliva, sweat or breath," said the researchers from University of Hanover, Germany.
The sensor uses the optical phenomenon of Surface Plasmon Resonance (SPR) which occurs when light causes electrons on the surface of a thin film to jostle to detect the composition of a liquid or the presence of particular biomolecules or trace gases.
"We have the potential to develop small and robust lab-on-a-chip devices for smartphones. So, surface plasmon resonance sensors could become ubiquitous now," said study co-author Kort Bremer.
In case of medical applications, the sensor readings can be combined with the Global Positioning System (GPS) signal of a smartphone and users can then be guided to the next drug store, hospital or the ambulance.
Surface plasmon resonance is a phenomenon commonly used for biosensing, but typically requires bulky lab equipment involving both a light detector and light source.
Fortunately, smartphones already have both of these, allowing the minimalist, U-shaped device the researchers designed to consist solely of a 400-micrometer diameter core multimode fibre with a silver-coated sensing region.
In subsequent experiments, the sensitivity of the device was tested using various concentrations of glycerol, and the team confirmed it was on par with current equipment, at a fraction of the cost and size.
The results appeared in the journal Optics Express.