Abstract
Introduction: Dopamine is one of the key
neurotransmitters (NTs) in nature, which plays
a crucial role in the mammalian central nervous
system (CNS). Its selective determination in the
biological fluids is an essential need in the field
of biomedicine studies.
Methods: In this work, an amperometric
sensor was developed using Nafion-coated
cadmium pentacyanonitrosylferrate (CdPCNF)
modified glassy carbon (GC) electrode
(Nafion|CdPCNF|GC electrode) as an
electrocatalyst to detect dopamine (DA) in human serum samples. To develop this sensor, the
surface of bare GC electrode was coated with the film of CdPCNF through an electropolymerization
method and then the modified electrode was coated with Nafion to minimize interferences,
especially those arising from the presence of anionic compounds. The electrocatalytic behavior
of the modified electrodes was studied using the cyclic voltammetry and amperometry, and then
the ability of the sensor for the determination of DA in synthetic and biological samples was
investigated.
Results: The modified electrode was showed a significant electrocatalytic activity for the oxidation
of DA at pH 7.4. The limit of detection (LOD) was 0.7 µM and also no interference effects arose
from ascorbic acid (AA), uric acid (UA) or the other biological NTs was observed in the DA
detection using the modified Nafion|CdPCNF|GC electrode.
Conclusion: In comparison with the bare electrode, the Nafion|CdPCNF|GC electrode could
determine DA in the biological samples with adequate sensitivity and selectivity. Therefore, we
propose that the modified electrode is utilizable as an amperometric DA sensor for the biological
sample analysis.