We have investigated the functionalization of PDMS films for the development of a microfluidic detection chamber for biosensing applications. As successful sensing requires a stable, reproducible and specific detection surface, we have developed a silanization protocol for biomolecule grafting. Using water contact angle, Energy Dispersive X-Ray Spectroscopy and fluorescence microscopy, we extensively characterized the PDMS after silanization with 3-aminopropyltriethoxysilane. Finally, the protocol has been successfully integrated into a fluidic channel, opening new perspectives for bioMEMS applications.