An optofluidic architecture for label free, highly parallel, detection of molecular interactions is based on the use of optically resonant devices whose resonant wavelength is shifted due to a local change in refractive index caused by a positive binding event between a surface bound molecule and its solution phase target. These devices have an extremely low limit of detection and are compatible with aqueous environments. The device combines the sensitivity (limit of detection) of nanosensor technology with the parallelity of the microarray type format.