Abstract
This work demonstrates a facile electropolymerization of a
dl
-methionine (
dl
-met) conducting polymeric film on a gold nanoparticle (AuNPs)-modified glassy carbon electrode (GCE). The resulting sensor was successfully applied for the sensitive detection of paroxetine·HCl (PRX), a selective serotonin (5-HT) reuptake inhibitor (SSRIs), in its pharmaceutical formulations. The sensor was characterized morphologically using scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM) and electrochemical techniques such as differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The proposed sensor, poly (
dl
-met)/AuNPs-GCE, exhibited a linear response range from 5 × 10
−11
to 5 × 10
−8
M and from 5 × 10
−8
to 1 × 10
−4
M using DPV with lowest limit of detection (LOD = 1 × 10
−11
M) based on (S/N = 3). The poly (
dl
-met)/AuNPs-GCE sensor was successfully applied for PRX determination in three different pharmaceutical formulations with percent recoveries between 96.29% and 103.40% ± SD (±0.02 and ±0.58, respectively).