The efficacy of the Nafion® blended CTAB protected Au nanoparticles for the electrochemical detection of tramadol in wastewater: A parametric investigation

Abstract

In an effort to develop a facile and rapid electrochemical sensing protocol for the detection of tramadol in wastewater, the glassy carbon electrode (GCE) was modified with the blend of cetyltrimethylammonium bromide (CTAB) protected Au nanoparticles (Au NPs) and Nafion®. The characteristic surface plasmon band at 525nm and the fading of the NH bands in the absorption and the FTIR spectra revealed the metallic nature and interaction of Au NPs with CTAB molecules. The dispersion of the protected and unprotected Au NPs at the surface of the GCE was investigated by atomic force microscopy (AFM). The charge transfer behavior of the fabricated Nafion®/CTAB-Au/GC electrode was investigated by electrochemical AC impedance spectroscopy (EIS). The significantly enhanced response of the polymer distributed CTAB protected Au NPs for the detection of tramadol revealed the salient role of Nafion® matrix in facilitating the charge transfer. The square wave anodic stripping voltammetry (SWASV) analysis was employed to quantify the amount of tramadol. Prior to the application on real wastewater samples, the experimental variables for sensitive detection such as SWASV parameters, deposition potential, deposition time, and pH were optimized. The SWASV response of Nafion®/CTAB-Au/GCE was linear over the 0.5–1μg/mL and 2–12μg/mL ranges with a detection limit (S/N=3) of 3×10−4μg/mL. The fabricated electrode exhibited sustained performance for the detection of tramadol in the repeated scans over a prolonged period.