5-[o-(4-Bromine amyloxy)phenyl]-10,15,20-triphenylporphrin (o-BrPETPP) was electropolymerized on a glassy carbon electrode (GCE), and the electrocatalytic properties of the prepared film electrode response to dopamine (DA) oxidation were investigated. A stable o-BrPETPP film was formed on the GCE under ultrasonic irradiation through a potentiodynamic process in 0.1 M H2SO4 between -1.1 V and 2.2 V versus a saturated calomel electrode (SCE) at a scan rate of 0.1 V s-1. The film electrode showed high selectivity for DA in the presence of ascorbic acid (AA) and uric acid (UA), and a 6-fold greater sensitivity to DA than that of the bare GCE. In the 0.05 mol L-1 phosphate buffer (pH 6.0), there was a linear relationship between the oxidation current and the concentration of DA solution in the range of 5 × 10-7 mol L-1 to 3 × 10-5 mol L-1. The electrode had a detection limit of 6.0 × 10-8 mol L-1(S/N = 3) when the differential pulse voltammetric (DPV) method was used. In addition, the charge transfer rate constant k = 0.0703 cm s-1, the transfer coefficient α = 0.709, the electron number involved in the rate determining step nα = 0.952, and the diffusion coefficient Do = 3.54 10-5 cm2 s-1 were determined. The o-BrPETPP film electrode provides high stability, sensitivity, and selectivity for DA oxidation.
Bibliographical noteFunding Information:
This work was financially supported by the National Natural Science Foundation of China (No. 20475018), and the Nature Science Foundation of Guangdong (No. 07006544) and Department of Education (No. 05Z008).
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)