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Carbon Nanoparticle Surface Electrochemistry: High‐Density Covalent Immobilisation and Pore‐Reactivity of 9,10‐Anthraquinone
Author(s) -
Watkins John D.,
Lawrence Katherine,
Taylor James E.,
James Tony D.,
Bull Steven D.,
Marken Frank
Publication year - 2011
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201100051
Subject(s) - anthraquinone , chemistry , nanoparticle , electrochemistry , glassy carbon , reactivity (psychology) , carbon fibers , inorganic chemistry , covalent bond , photochemistry , organic chemistry , cyclic voltammetry , electrode , nanotechnology , materials science , composite number , medicine , alternative medicine , pathology , composite material
2‐Bromomethyl‐9,10‐anthraquinone is covalently bound to carbon nanoparticle surfaces (Emperor 2000, Cabot Corp., with sulphonamide groups, ca. 9 to 18 nm diameter) with a coverage of ca. 250 anthraquinone molecules per particle (ca. 180 Å 2 per anthraquinone). The resulting hydrophobic carbon particles are dispersed in ethanol and coated onto glassy carbon electrodes. Electrochemical experiments are reported demonstrating the effect of surface coverage, scan rate, and pH. A linear shift in reversible potential of ca. 59 mV per pH unit from pH 2 to 12 is observed consistent with the reversible 2‐electron 2‐proton reduction of anthraquinone. High density of anthraquinone in carbon nanoparticle aggregates causes buffer capacity effects. Binding of hydrophobic tetraphenylborate anions into carbon nanoparticle aggregate pores is demonstrated. Applications in buffer characterisation and pH‐sensing are discussed.