Our group succeeded in developing a fully biocompatible nano-optical sensor by using silk, extracted from cocoons. This achievement was published on April 1st in the online issue of Nano Letters, a renowned international academic journal in the field of nano studies. The paper is entitled “A highly tunable and fully biocompatible silk nanoplasmonic optical biosensor.” Our sensor is fully composed of biocompatible materials, gold and silk, and it also has a high sensitivity. Therefore, the sensor is expected to be widely used for smart healthcare, which is emerging as a next-generation growth engine for IT companies. Our team extracted aqueous silk protein from cocoons and created nano optical elements with a gold nanostructure by utilizing semiconductor processing technology. Glucose detection of our sensor is 5-6 times more sensitive than those of conventional plasmonic biosensors. Professor Kim explained, “By inserting a very thin silk film inside a gold nanostructure, the volume of the film expands as it responds to water or chemical substances such as alcohol,” adding, “We can achieve high sensitivity as the resonance wavelength to which nano-optical elements respond changes with the films’ expansion.” Professor Kim went on to say, “The research is significant in that it has opened the possibility for silk protein, which has only been considered a fiber to this point, to be recreated as a human-body-friendly bio sensor,” adding, “I expect the research to provide insight for future studies regarding the healthcare market.” The study was conducted with the support for basic research projects (for new researchers and leading research centers) carried out by the Ministry of Science, ICT and Future Planning and the National Research Foundation of Korea.