title: Ligand-modified multi-walled carbon nanotubes for potentiometric detection of silver.
abstract: Three novel hybrid materials have been synthesized by ligands: N-(2-vinylsulfanyl-ethylidene)-benzene-1,2-dimine (SBD), N-pyridin-2-ylmethylene-benzene-1,2-dimine (NBD) and N-furan-2-ylmethylene-benzene-1,2-dimine (OBD), covalently linking to multi-walled carbon nanotubes (MWCNTs). These MWCNT hybrid materials were used both as ionophores and as ion-to-electron transducers to construct Ag(+) carbon paste electrodes. The resulting electrodes show higher selectivity to Ag(+) than other cations tested. Among the three electrodes, the electrode based on SBD-g-MWCNTs with optimum composition shows the best performance to Ag(+). It exhibits an excellent Nernstian response to Ag(+) in the concentration range from 8.8 × 10(-8) to 1.0 × 10(-1) M with a detection limit of 6.3 × 10(-8) M, and it can also be used over a wide pH range of 3.0-8.0 with a quick response time of 5 s. The response mechanism of the proposed electrode was also investigated by using AC impedance and UV-vis spectroscopy techniques.
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, P. R. China.
authors.forename: Chunli
authors.initials: C
authors.lastname: Yang
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
authors.forename: Junxiang
authors.initials: J
authors.lastname: Guo
authors.forename: Feng
authors.initials: F
authors.lastname: Jia