Photonic crystal microring resonator for labelfree biosensing

A label-free optical biosensor based on a one-dimensional photonic crystal microring resonator with enhanced light-matter interaction is demonstrated. More than a 2-fold improvement in volumetric and surface sensing sensitivity is achieved compared to conventional microring sensors. The experimental bulk detection sensitivity is similar to 248nm/RIU and label-free detection of DNA and proteins is reported at the nanomolar scale. With a minimum feature size greater than 100nm, the photonic crystal microring resonator biosensor can be fabricated with the same standard lithographic techniques used to mass fabricate conventional microring resonators. (C) 2017 Optical Society of America