title: Label-free optical detection of peptide synthesis on a porous silicon scaffold/sensor.
abstract: Mesoporous porous silicon (PSi) microcavity sensors are used to conduct conventional solid-phase peptide synthesis. The sensor optical response provides a convenient means to monitor the synthesis reaction in a nondestructive manner. Measurements indicate that peptide synthesis occurs only when the PSi sensor/scaffold is amine-terminated using, for example, the amino silane or deprotected acid-labile Rink linker. Equivalent coupling efficiencies of the first amino acid to both amine terminations are observed. Kinetic studies indicate that coupling reactions are 90% complete in 1 h. Quantitative analysis of the optical response following the synthesis of homo-oligopeptides (4-mers) suggests that coupling efficiencies and/or optical thickness changes depend on the peptide length. The synthesis of the cell adhesive oligopeptide (RGD) was monitored by the optical sensor response and validated by the cell culture of primary dermal fibroblasts. Secondary ion mass spectrometry (SIMS) analysis successfully detected peptide on the silicon wafer adjacent to the PSi. Our findings suggest the potential to exploit the high surface area, efficient coupling, and intrinsic optical detection properties of PSi for label-free high-throughput screening.
authors.affiliation: Department of Microbiology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, New York 14642, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Furbert
authors.forename: Caiyan
authors.initials: C
authors.lastname: Lu
authors.forename: Nicholas
authors.initials: N
authors.lastname: Winograd
authors.forename: Lisa
authors.initials: L
authors.lastname: DeLouise
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D002478:Cells, Cultured; D004566:Electrodes; D005347:Fibroblasts / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry; D055095:Optics and Photonics; D010316:Particle Size; D016062:Porosity; D012825:Silicon / Q000737:chemistry*; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods; D013499:Surface Properties
chemical_list: D000596:Amino Acids; D009842:Oligopeptides; C047981:arginyl-glycyl-aspartic acid; D012825:Silicon