Biosensing using Porous Silicon Photonic Bandgap Structures

Photonic bandgap (PBG) structures have remarkable optical properties that can be exploited for biosensing applications. We describe the fabrication of 1-D PBG biosensors using porous silicon. The optical properties of porous silicon PBGs are sensitive to small changes of refractive index in the porous layers, which makes them a good sensing platform capable of detecting binding of the target molecules to the bioreceptors. The material nanostructure and device configuration that lead to optimum performance of the devices are investigated in detail by modeling the optical response. It is shown that porous silicon based PBG sensors are useful for detecting biological matter, from small molecules to larger proteins.