In this work the determination of ascorbic acid (AA) at glassy carbon
electrode (GCE) modified with a perforated film produced by reduction of
diazonium generated in situ from p-phenylenediamine (PD) is reported. Holes
were intentionally created in the modifier film by stripping a pre-deposited
gold nanoparticles. The modified electrodes were electrochemically
characterized by common redox probes: hydroquinone, ferrocyanide and
hexamineruthenium(III). The cyclic voltammetric and amperometric response of
AA using the modified electrodes was compared with that of bare GCE. The bare
GCE showed a linear response to AA in the concentration range of 5 mM to 45
mM with detection limit of 1.656 mM and the modified GCE showed a linear
response to AA in the concentration range of 5 ?M to 45 ?M with detection
limit of 0.123 ?M. The effect of potential intereferents on amperometric
signal of AA at the modified GCE was examined and found to be minimal. The
inter-electrode reproducibility, stability, and accuracy were determined. The
modified electrode showed excellent inter-electrode reproducibility, accuracy
and stability. The modified electrode reported is a promising candidate for
use in electroanalysis of AA.
Electrochemical determination of ascorbic acid at p-phenylenediamine film-holes modified glassy carbon electrode
