title: Peptide-nanowire hybrid materials for selective sensing of small molecules.
abstract: The development of a miniaturized sensing platform for the selective detection of chemical odorants could stimulate exciting scientific and technological opportunities. Oligopeptides are robust substrates for the selective recognition of a variety of chemical and biological species. Likewise, semiconducting nanowires are extremely sensitive gas sensors. Here we explore the possibilities and chemistries of linking peptides to silicon nanowire sensors for the selective detection of small molecules. The silica surface of the nanowires is passivated with peptides using amide coupling chemistry. The peptide/nanowire sensors can be designed, through the peptide sequence, to exhibit orthogonal responses to acetic acid and ammonia vapors, and can detect traces of these gases from "chemically camouflaged" mixtures. Through both theory and experiment, we find that this sensing selectivity arises from both acid/base reactivity and from molecular structure. These results provide a model platform for what can be achieved in terms of selective and sensitive "electronic noses."
authors.affiliation: Kavli NanoScience Institute and the Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: McAlpine
authors.forename: Heather D
authors.initials: HD
authors.lastname: Agnew
authors.forename: Rosemary D
authors.initials: RD
authors.lastname: Rohde
authors.forename: Mario
authors.initials: M
authors.lastname: Blanco
authors.forename: Habib
authors.initials: H
authors.lastname: Ahmad
authors.forename: Andreea D
authors.initials: AD
authors.lastname: Stuparu
authors.forename: William A
authors.initials: WA
authors.lastname: Goddard
authors.forename: James R
authors.initials: JR
authors.lastname: Heath
mesh_terms: D019342:Acetic Acid / Q000032:analysis* / Q000737:chemistry; D000641:Ammonia / Q000032:analysis* / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D008956:Models, Chemical; D053770:Nanowires / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry
chemical_list: D009842:Oligopeptides; D000641:Ammonia; D019342:Acetic Acid; D012825:Silicon