title: SU-8 photolithography on reactive plasma thin-films: coated microwells for peptide display.
abstract: We have developed a technique to create 50μm-deep microwells coated with a reactive and robust thin film, which withstands photolithographic processing, and allows for subsequent chemical functionalisation with biological cues (i.e. peptides). First, plasma polymerisation of 1-bromopropane was used to generate a bromine-functionalised thin film (BrPP) on a substrate of silicon wafer. Second, an epoxy functionalised polymer UV photoresist, SU-8, was deposited and developed to create 50μm-deep patterned microwells that display the BrPP coating at their base. Third, amino acids or peptides were selectively attached to the bottom of the microwells through bromine displacement by an amine or thiol nucleophile. Each surface functionalisation step was monitored by XPS, AFM, and contact angle measurements. These functionalities were then used as linkers to immobilise enzymes (e.g. HRP), which retain activity at the end of the process as shown by a biochemical activity assay. Peptide promoters of cell attachment were also immobilised and their functionality was evaluated using an L929 fibroblast adhesion assay. In conclusion, this work describes an innovative combination of plasma thin film deposition and photolithography to create 50μm-deep functionalised microwells for peptide display in biological applications.
authors.affiliation: CSIRO Materials Science and Engineering, Bayview Avenue, Clayton, VIC 3168, Australia. marchesan.silvia@gmail.com
authors.forename: Silvia
authors.initials: S
authors.lastname: Marchesan
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Easton
authors.forename: Katie E
authors.initials: KE
authors.lastname: Styan
authors.forename: Patrick
authors.initials: P
authors.lastname: Leech
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Gengenbach
authors.forename: John S
authors.initials: JS
authors.lastname: Forsythe
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Hartley
mesh_terms: D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000494:pharmacology; D004800:Enzymes, Immobilized / Q000737:chemistry; D004852:Epoxy Compounds / Q000737:chemistry*; D005347:Fibroblasts / Q000187:drug effects; D006735:Horseradish Peroxidase / Q000737:chemistry; D006842:Hydrocarbons, Brominated / Q000737:chemistry; D018625:Microscopy, Atomic Force; D010455:Peptides / Q000737:chemistry*; D055668:Photochemical Processes; D056951:Photoelectron Spectroscopy; D011108:Polymers / Q000737:chemistry*; D040081:Protein Array Analysis / Q000295:instrumentation* / Q000379:methods; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D004852:Epoxy Compounds; D006842:Hydrocarbons, Brominated; D010455:Peptides; D011108:Polymers; C520895:SU-8 compound; D006735:Horseradish Peroxidase; C118559:1-bromopropane; D012825:Silicon