title: Chemical patterning on preformed porous silicon photonic crystals: towards multiplex detection of protease activity at precise positions†Electronic supplementary information (ESI) available: SEM images, XPS result and more optical reflectivity data. See DOI: 10.1039/c4tb00281dClick here for additional data file.
abstract: Porous silicon (PSi) rugate filters modified with alkyne-terminated monolayers were chemically patterned using a combination of photolithography of photoresist and click chemistry. Two chemical functionalities were obtained by conjugating,viaclick reactions, ethylene glycol moieties containing two different terminal groups to discrete areas towards the exterior of a PSi rugate filter. The patterning of biological species to the functionalized surface was demonstrated through the conjugation of fluorescein isothiocyanate labelled bovine serum albumin (FITC-BSA). Fluorescence microscopy showed selective positioning of FITC-BSA at discretely functionalized areas. Meanwhile, the optical information from precisely defined positions on the patterned surface was monitored by optical reflectivity measurements. The optical measurements revealed successful step-wise chemical functionalization followed by immobilization of gelatin. Multiplex detection of protease activity from different array elements on the patterned surface was demonstrated by monitoring the blue shifts in the reflectivity spectra resulted from the digestion of gelatin by subtilisin. Precise information from both individual elements and average population was acquired. This technique is important for the development of PSi into a microarray platform for highly parallel biosensing applications, especially for cell-based assays.
authors.affiliation: School of Chemistry and the Australian Centre for NanoMedicine , University of New South Wales , Sydney 2052 , Australia . Email: justin.gooding@unsw.edu.au.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: School of Chemistry and the Australian Centre for NanoMedicine , University of New South Wales , Sydney 2052 , Australia . Email: justin.gooding@unsw.edu.au.
authors.forename: Alexander H
authors.initials: AH
authors.lastname: Soeriyadi
authors.affiliation: School of Chemistry and the Australian Centre for NanoMedicine , University of New South Wales , Sydney 2052 , Australia . Email: justin.gooding@unsw.edu.au.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Parker
authors.affiliation: School of Physics , University of New South Wales , Sydney 2052 , Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Reece
authors.affiliation: School of Chemistry and the Australian Centre for NanoMedicine , University of New South Wales , Sydney 2052 , Australia . Email: justin.gooding@unsw.edu.au.
authors.forename: J Justin
authors.initials: JJ
authors.lastname: Gooding