London, July 2:
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. (IANS)