Physicists develop miniature Raman laser sensors for single nanoparticle detection
Optical sensing of nanoscale objects with ultrahigh sensitivity is highly desirable for applications in various fields, such as in early-stage diagnosis of human diseases and in environmental monitoring, as well as in homeland security. The ultimate sensitivity of a nanoparticle sensor is expected to be at the level of a single nanoparticle response. Very recently, a group led by Professors Xiao Yun-Feng and Gong Qihuang from Peking University, has developed a novel microcavity Raman-laser sensor, and realized single nanoparticle detection in both air and in an aqueous environment. The smallest nanoparticle they detected in water was 20 nanometers in radius. Their new experimental results were published in Proceedings of National Academy of Sciences online Early Edition.