title: Cavitand-functionalized SWCNTs for N-methylammonium detection.
abstract: Single-walled carbon nanotubes (SWCNTs) have been functionalized with highly selective tetraphosphonate cavitand receptors. The binding of charged N-methylammonium species to the functionalized SWCNTs was analyzed by X-ray photoelectron spectroscopy and confirmed by (31)P MAS NMR spectroscopy. The cavitand-functionalized SWCNTs were shown to function as chemiresistive sensory materials for the detection of sarcosine and its ethyl ester hydrochloride in water with high selectivity at concentrations as low as 0.02 mM. Exposure to sarcosine and its derivative resulted in an increased conductance, in contrast to a decreased conductance response observed for potential interferents such as the structurally related glycine ethyl ester hydrochloride.
authors.affiliation: Department of Chemistry and Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Marco
authors.initials: M
authors.lastname: Dionisio
authors.forename: Jan M
authors.initials: JM
authors.lastname: Schnorr
authors.forename: Vladimir K
authors.initials: VK
authors.lastname: Michaelis
authors.forename: Robert G
authors.initials: RG
authors.lastname: Griffin
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Swager
authors.forename: Enrico
authors.initials: E
authors.lastname: Dalcanale
mesh_terms: D002244:Carbon; D004988:Ethers, Cyclic / Q000737:chemistry*; D008744:Methylamines / Q000032:analysis*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D000644:Quaternary Ammonium Compounds / Q000032:analysis*; D012118:Resorcinols / Q000737:chemistry*; D012521:Sarcosine / Q000032:analysis; D013057:Spectrum Analysis; D013499:Surface Properties; D014867:Water
chemical_list: D004988:Ethers, Cyclic; D008744:Methylamines; D037742:Nanotubes, Carbon; D000644:Quaternary Ammonium Compounds; D012118:Resorcinols; C442939:cavitand; D014867:Water; D002244:Carbon; C027451:methylamine; D012521:Sarcosine