Monitoring of Anthracene Using Nanoscale Au–Cu Bimetallic Alloy Nanoparticles Synthesized with Various Compositions

[Image: see text] Bimetallic alloy Au–Cu nanoparticles (Au–Cu alloy NPs) were synthesized using a chemical reduction method for sensing applications. Electronic absorption spectroscopy (UV–visible spectroscopy), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used for the confirmation and morphological studies of the synthesized nanoparticles. The composition of Au–Cu alloy NPs was studied by energy-dispersive spectroscopy (EDS). The high crystallinity of Au–Cu alloy NPs was demonstrated by XRD analysis. Both XRD and SEM analyses revealed that the nanoparticles’ size ranges from 15 to 25 nm. Pyrrole was polymerized into polypyrrole (PPy) over a neat and clean glassy carbon electrode (GCE) by potentiodynamic polymerization. The sensitivity of GCE was improved by modifying it into a composite electrode. The composite electrode was developed by coating GCE with an overoxidized PPy polymer followed by Au–Cu alloy NPs. The ratio of Au and Cu was carefully controlled. The composite electrode (PPyox/Au–Cu/GCE) successfully detected an environmental toxin anthracene with a detection limit of 0.15 μM, as evidenced by cyclic voltammetry (CV), square-wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS).