Analysis of single nanoparticle detection by using 3-dimensionally confined optofluidic ring resonators

This study investigates the ability of an optofluidic ring resonator (OFRR) in single nanoparticle detection in liquid. This work theoretically analyzes the sensing capability of the microbottle and microbubble ring resonators under different conditions. Results show that about 10-fold sensitivity enhancement over a microsphere biosensor can be achieved and the smallest detectable nanoparticle is estimated to be less than 20 nm in radius.The extension of the detection capability to smaller nanoparticle sizes enables the detection of more types of important and lethal viruses (such as SARS virus and dengue virus with radii below 50 nm). The unprecedented sensitivity in combination of the excellent microfluidics makes the OFRR a very promising sensing platform for detection of various sizes of bio/chemical species.