A new nanoscale sensor has been developed that can help detect cytokines — molecules that play a critical role in cellular response to infection, inflammation, trauma and disease. Researchers at the Australian Research Council Centre of Excellence for Nanoscale Biophotonics created the modified graphene quantum dot (GQD) sensor that allows ultra-small amounts of cytokines to be identified in and around cells. Potential applications include biomedical research. Researcher and associate prof. Guozhen Liu. Courtesy of the Australian Research Council Centre of Excellence for Nanoscale Biophotonics. Cytokines are molecules secreted by the cells of the immune system. Scientist Guozhen Liu said the release of certain cytokines by the body is frequently symptomatic of a disease or health-related issue. “Monitoring cytokine secretions at the cellular and subcellular level has enormous value in our understanding of basic physiology and how the body is actually working.” Cytokine molecules are difficult to measure and quantify due to their small size and dynamic and transient nature. “What we’ve been able to do is to design and make a sensor that is so small that it can easily penetrate inside cells,” saide Liu. “Moreover, unlike other sensors, it only responds when the cytokine is present. To this aim we have connected GQDs to cytokine-sensing DNA molecules known as aptamers.” Ewa Goldys, deputy director for the Centre for Nanoscale Biophotonics, believes that the innovative GQD sensing technology they developed has potential for widespread applications. “We see these graphene quantum dot sensors as being excellent candidates for many other biomedical applications such as DNA and protein analysis, intracellular tracking, as well as for monitoring of other cell-secreted products in the body,” said Goldys. Their research has been published in the science journal Nanoscale (doi: 10.1039/C6NR09381G).