Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10559518 | Talanta | 2011 | 10 Pages |
Abstract
The pre-grafted screen-printed gold electrode modified with phenyl-amino monolayer was investigated for covalent immobilization of phenyl-amine functionalized single-walled carbon nanotubes (PA-SWCNT) and metal tetra-amino phthalocyanine (MTAPc) using Schiff-base reactions with benzene-1,4-dicarbaldehyde (BDCA) as cross-linker. The PA-SWCNT and MTAPc modified electrodes were applied as hybrids for electrochemical sensing of H2O2. The step-by-step fabrication of the electrode was followed using electrochemistry, impedance spectroscopy, scanning electron microscopy and Raman spectroscopy and all these techniques confirmed the fabrication and the immobilization of PA-SWCNT, MnTAPc and CoTAPc onto gold surfaces. The apparent electron transfer constant (kapp) showed that the carbon nanotubes and metallo-phthalocyanines hybrids possess good electron transfer properties compared to the bare, pre-grafted and the MTAPc modified gold electrode surfaces without PA-SWCNT. The electrochemical sensing of hydrogen peroxide was successful with PA-SWCNT-MTAPc hybrid systems showing higher electrocatalytic currents compared to the other electrodes. The analytical parameters obtained using chronoamperometry gave good linearity at H2O2 concentrations ranging from 1.0 to 30.0 μmol Lâ1. The values for the limit of detection (LoD) were found to be of the orders of 10â7 M using the 3δ for all the electrodes. The PA-SWCNT-MTAPc modified SPAuEs were much more sensitive compared to PA-MTAPc modified SPAuEs.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Philani Mashazi, Tawanda Mugadza, Ndabenhle Sosibo, Phumlani Mdluli, Sibulelo Vilakazi, Tebello Nyokong,