Optical evanescent microsensors have attracted considerable research interests since they can detect unlabelled molecules and monitor their interactions in real time and in situ with ultrahigh sensitivity, fast response, and miniature footprint. However, these sensors utilize the weak tail of evanescence field rather than the peak of the electromagnetic field on the sensing surface, limiting their sensitivities. Very recently, scientists from Professor Xiao Yun-Feng’s group at Peking University, collaborating with Dr. Chen You-Ling at Institute of Semiconductors, CAS, have proposed the interface whispering gallery mode (WGM) with the electromagnetic field peaked at the sensing surface of a microbubble cavity, and demonstrated the detection of single DNA molecules with the molecular weight of 8 kDa. This work has been published online in PNAS.
Click here for original story, Single-molecule optofluidic microsensor with interface whispering gallery modes
Source: Phys.org