Fabrication of a new electrochemical imprinted sensor for determination of ketamine based on modified polytyramine/sol-gel/f-MWCNTs@AuNPs nanocomposite/pencil graphite electrode

This paper proposes a new strategy for measurement of ketamine through one-step electropolymerization of the molecularly imprinted polymer (MIP) composed of polytyramine (pty), sol-gel, functionalized multiwall carbon nanotubes@gold nanoparticles (f-MWCNTs@AuNPs) nanocomposite and ketamine on a pencil graphite electrode (PGE) by cyclic voltammetric (CV) technique. F-MWCNTs@AuNPs nanocomposite was entrapped within the polymer network to enhance the electron transfer rate and sensitivity of the fabricated sensor. The f-MWCNTs@AuNPs nanocomposite was synthesized by the chemical reduction method and its structure characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDX). The electrochemical behavior of the modified electrode was investigated using cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV) techniques. Under the optimized experimental conditions, the calibration curve of the MIP electrode was plotted and two dynamic linear ranges from 1.0 to 50.0 nM and 50.0-1000.0 nM, with a limit of detection (LOD) of 0.7 nM were obtained for quantitative measurement of ketamine in solution. The obtained results show that the proposed sensor has an excellent stability, good reproducibility and repeatability, and high sensitivity and selectivity towards the ketamine molecules. Furthermore, the electrochemical imprinted sensor was successfully applied for determination of ketamine in biological samples with satisfactory results.