Biofunctionalization of free-standing porous silicon films for self-assembly of photonic devices

Here we test chemical strategies for the fabrication of free-standing porous silicon thin films that are covalently modified on one of their faces with biorecognition elements to guide the vertical self-assembly of optical structures. Chemical modification via hydrosilylation of alkenes followed by coupling of biomolecules is carried out after the porous silicon film is lifted off from the silicon wafer to avoid damage to the organic monolayer during the lift-off step. Micron-sized biotinylated particles produced from asymmetrically modified porous silicon films are deposited via biorecognition in the correct orientation onto a substrate modified with avidin to form optical resonant microcavities.