Kolkata, Sep 25 Indian Institute of Technology Kharagpur on Friday said its researchers have developed a highly sensitive sensor technology that could allow ordinary smartphone cameras to detect extremely tiny objects which are invisible to the naked eye.
The institute said the technology, built in collaboration with scientists from the University of Illinois Urbana-Champaign, would likely help develop low-cost, portable devices for medical testing and other applications in which very small quantities of a substance need to be detected.
The researchers said the technology could be particularly useful when combined with smartphones, which are increasingly available in both urban and rural areas.
The new photonic crystal-based platform they developed can increase the interaction between light and matter by nearly 1,300 times and detect substances at the attomolar level — a scale previously invisible to phone cameras.
Its integration with artificial intelligence and machine learning could open up further possibilities in healthcare diagnostics and other fields, the statement said.
The system works by strengthening very weak light signals produced by special reporter molecules called rhodamine. The amplified signals can then be captured by a commonly available smartphone camera, according to the institute.
At the centre of the technology is a photonic crystal made up of a regular arrangement of extremely tiny structures, each about a thousand times smaller than the diameter of a human hair.
“Photonic crystals” are structures that can control the movement of light. Similar natural structures can be found in butterfly wings, peacock feathers, sea mice and opal stones, the institute said.
Prof Shivakiran Bhaktha and his team at IIT Kharagpur have been working on designing and making such photonic structures for sensing applications.
Their work was combined with the bionanophotonics research of Prof Brian T Cunningham and his team at UIUC.
The researchers further engineered the photonic crystals using nanoparticles of gold, titania and graphene oxide.
According to the institute, these tiny structures create areas known as optical “hot spots”, where light is concentrated into a very small space. This greatly increases the interaction between light and matter and helps amplify signals that would otherwise be too weak to detect.
The institute said a major advantage of the technology is that it could reduce the need for costly and highly sensitive detection equipment. By amplifying weak signals, the new platform allows a regular smartphone camera to be used as the detector.
The technology could therefore help make diagnostic equipment smaller and more portable, the researchers said.
While early disease detection and healthcare are important potential applications, the platform could also be used in other areas requiring quick, affordable and highly sensitive detection.
The research has been published in the journal Advanced Optical Materials and has also been featured on its cover, IIT Kharagpur said.
(PTI News)
