Recently, Professor Wang Xiuhong's research team in the Institute of Laser Engineering, Faculty of Materials and Manufacturing, Beijing University of Technology, has published an online paper entitled "Demonstration of intracellular real-time molecular quantification via FRET-enhanced optical microcavity" in a highly regarded journal Nature Communications reporting their latest research results. Beijing University of Technology is the first and the only author affiliation. The first authors are master student Wang Yaping, visiting scholar Marion C. Lang from Germany and master student Lu Jinsong. This research was supported by the National Natural Science Foundation of China, the National Key Research and Development Program and the Natural Science Foundation of Beijing.

Single cell analysis is crucial for elucidating cellular diversity and heterogeneity as well as for medical diagnostics operating at the ultimate detection limit. Real-time quantification of intracellular molecules remains challenging due to the extreme low quantity and limitations of the current techniques. In view of this, Wang and her team present a method to enhance the sensitivity of the active mode optical microcavity sensing using the fluorescence resonance energy transfer (FRET) mechanism. The mutual effects of optical microcavity and FRET greatly enhances the sensing performance by four orders of magnitude, enabling quantitative molecular analysis at single cell resolution. By achieving high sensitivity at single cell level, their approach provides a path towards real-time quantitative analysis of intracellular molecules.