Highly sensitive single nanoparticle sensor using slot-bridge-slot nanobeam cavity

Аннотация

This work presents a single nanoparticle sensor based on a slot-bridge-slot photonic crystal nanobeam cavity. To investigate the sensor feasibility for single particle detection, the resonance wavelength shift of the cavity mode is calculated by perturbation theory and the simulation results of the mode profile.  A mode volume of is realized, which is reduced by a factor of  times in comparison with nanobeam cavity. We demonstrate the detection of streptavidin molecules with radius ~ 2.65 nm with large resonant wavelength shift (25.4 pm). To the best of our knowledge, this represents the larger wavelength shift ever reported in single nanoparticle sensors. The proposed sensor is a promising candidate for a wide range of sensing applications and for fundamental studies.