Optimization of whispering gallery mode sensor design for applications in biosensing

Whispering gallery modes (WGM) within microsphere cavities have demonstrated the ability to provide label-free, highly sensitive and selective detection down to a single molecule level, emerging as a promising technology for future biosensing applications. Currently however, the majority of biosensing work utilizing WGMs has been conducted in resonators made from either silica or polystyrene while other materials have been largely uninvestigated. This work looks to predict the optimal combinations of material, resonator size and excitation/coupling scheme to provide guidelines to assist in decision making when undertaking refractive index biosensing in a range of situations.