title: Photolithographic strategy for patterning preformed, chemically modified, porous silicon photonic crystal using click chemistry.
abstract: Porous silicon (PSi) is an ideal platform for label-free biosensing, and the development of porous silicon patterning will open a pathway to the development of highly parallel PSi biochips for detecting multiple analytes. The optical response of PSi photonic crystal is determined by the changes in the effective bulk refractive index resulting from reactions/events occurring within the internal pore space. Therefore, introducing precise chemical functionalities in the pores of PSi is essential to ensure device selectivity. Here we describe the fabrication of PSi patterns that possess discrete chemical functionalities that are restricted to precise locations. The key difference to previous patterning protocols for PSi is that the entire porous material is first modified with a self-assembled monolayer of a α,ω-diyne adsorbate prior to patterning using a microfabricated titanium mask. The distal alkyne moieties in the monolayer are then amenable to further selective modification by the archetypal "click" reaction, the copper catalyzed alkyne-azide cycloaddition (CuAAC), using the titanium mask as a resist. This type of patterning is suitable for further immobilization of biological recognition elements, and presents a new platform for highly parallel PSi biosensor for multiple detections.
authors.affiliation: School of Chemistry and the Australian Centre for NanoMedicine, University of New South Wales, Sydney 2052, Australia.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
authors.forename: Bakul
authors.initials: B
authors.lastname: Gupta
authors.forename: Bin
authors.initials: B
authors.lastname: Guan
authors.forename: Simone
authors.initials: S
authors.lastname: Ciampi
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Reece
authors.forename: J Justin
authors.initials: JJ
authors.lastname: Gooding
mesh_terms: D057930:Click Chemistry; D017785:Photons; D016062:Porosity; D012825:Silicon / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D014466:Ultraviolet Rays
chemical_list: D012825:Silicon