High sensitivity nanoparticle detection using optical microcavities

作者：Lu Tao^*; Lee Hansuek; Chen Tong; Herchak Steven; Kim Ji Hun; Fraser Scott E; Flagan Richard C; Vahala Kerry

来源：Proceedings of the National Academy of Sciences of the United States of America, 2011, 108(15): 5976-5979.

DOI：10.1073/pnas.1017962108

• biosensor
• nanodetector
• optical microcavity

We demonstrate a highly sensitive nanoparticle and virus detection method by using a thermal-stabilized reference interferometer in conjunction with an ultrahigh-Q microcavity. Sensitivity is sufficient to resolve shifts caused by binding of individual nanobeads in solution down to a record radius of 12.5 nm, a size approaching that of single protein molecules. A histogram of wavelength shift versus nanoparticle radius shows that particle size can be inferred from shift maxima. Additionally, the signal-to-noise ratio for detection of Influenza A virus is enhanced to 38:1 from the previously reported 3:1. The method does not use feedback stabilization of the probe laser. It is also observed that the conjunction of particle- induced backscatter and optical-path-induced shifts can be used to enhance detection signal-to-noise.

• 出版日期2011-4-12