Networked censors require miniaturized censors for realistic large scale deployment. We are developing an entire new versatile molecular sensor based on the plasmonic band gap phenomenon. It uses evanescent electromagnetic waves called surface plasmons which are collective excitation of electrons on an interface metal/dielectric. Contrary to existing surface plasmon based sensors, our detection mechanism is based on the properties of the propagation of surface plasmon waves through periodic nanostructures. This allows for a robust and embed- able detection system for on-field deployment.