posted on 2024-01-25, 20:06authored bySiyabonga Shoba, Allen Mambanda, Irvin Noel Booysen
Herein, the nanofabrication
and characterization of new conductive
materials, PANI-CoPc-fur (1) ((PANI = polyaniline and
CoPc-fur = tetra-4-(furan-2-methylthiophthalocyaninato)Co(II))
and PANI-CoPc-fur-f-MWCNTs (2) (f-MWCNTs = carboxylic acid-functionalized multiwalled carbon
nanotubes), are reported. Subsequently, an electrospun nanofiber (ENF)
composite of 2, encapsulated with a poly(vinyl acetate)
shell, was fabricated. The resultant core–shell nanoconjugated
fibers, ENFs-2, were adsorbed on a glassy carbon electrode
(GCE), followed by the immobilization of a permeable adhesion top
layer of Nafion (Nf) to render the chemically modified electrode,
GCE|ENFs-2-Nf. The electron-mediating properties of the
components within the film of GCE|ENFs-2-Nf synergistically
aided in promoting its electrocatalytic activities. Consequently,
the CME showed greater cyclic voltammetry (CV) peak currents compared
to the bare GCE and other modified electrodes, indicating its higher
sensitivity toward acetaminophen (APAP), an emerging water pollutant
of concern. The detection of APAP at the GCE|ENFs-2-Nf
attained by square-wave voltammetry (SWV) was linear from 10 to 200
μM of APAP and was reproducible (%RSD of 3.2%, N = 3). The respective calculated limits of detection and quantification
(LOD and LOQ) values of 0.094 and 0.28 μM were lower than those
acquired using other electrochemical techniques. Analysis of APAP
in the presence of commonly associated interferences metronidazole
(MTZ) and dopamine (DA) illustrated a significant separation between
the SWV peak potentials of APAP and MTZ, whereas there was some degree
of overlap between the SWV current responses of APAP and DA. The analytical
performance of the GCE|ENFs-2-Nf rendered a comparable
percentage recovery (104%) with that of liquid chromatography–mass
spectrometry (LC–MS) (106%).