Photonic crystal biosensors towards on-chip integration.

Photonic crystal technology has attracted large interest in the last years. The possibility to generate highly sensitive sensor elements with photonic crystal structures is very promising for medical or environmental applications. The low-cost fabrication on the mass scale is as advantageous as the compactness and reliability of photonic crystal biosensors. The possibility to integrate microfluidic channels together with photonic crystal structures allows for highly compact devices. This article reviews different types of photonic crystal sensors including 1D photonic crystal biosensors, biosensors with photonic crystal slabs, photonic crystal waveguide biosensors and biosensors with photonic crystal microcavities. Their applications in biomolecular and pathogen detection are highlighted. The sensitivities and the detection limits of the different biosensors are compared. The focus is on the possibilities to integrate photonic crystal biosensors on-chip.