The present article reviews two different optical biosensing mechanisms (based on evanescent wave detection) that can be implemented in a multibiosensor technology platform: surface plasmon resonance, and optoelectronic biosensing using integrated Mach-Zehnder interferometer devices. In the last case, the use of standard silicon microelectronics technology opens the possibility for further integration of optical, fluidics and electrical functions within a single optical sensing circuit leading to a complete lab-on-a-chip design solution