Multi-walled carbon nanotube/graphene oxide/poly(threonine) composite electrode for boosting electrochemical detection of paracetamol in biological samples

We developed an electrochemical sensing tool based on the electropolymerization of L-threonine (Thr) followed by the deposition of graphene oxide (GO) and multi-walled carbon nanotube (MWCNT) on the glassy carbon electrode (GCE). The surface morphological study of the proposed electrodes confirmed the formation of composites consisting of poly(Thr), MWCNT, and GO on the GCE by FE-SEM and the structural characterization of the MWCNT/GO composite was confirmed by Raman and ATR-IR analysis. The prepared electrode (MWCNT/ GO/Poly(Thr)/GCE) showed high catalytic activity for paracetamol (PCT) determination in comparison to bare GCE, Poly(Thr)/GCE, and MWCNT/GO/GCE. The proposed sensor exhibited an excellent linear response of MWCNT/GO/Poly(Thr)/GCE toward PCT with a limit of detection (LOD) of 0.16 mu M by differential pulse voltammetry. In the presence of norepinephrine (NEP) and folic acid (FA), the voltammetric signal of PCT was not significantly disturbed, revealing the good selectivity of the developed sensor. Moreover, the designed sensor displayed sufficient repeatability, satisfactory reproducibility, and acceptable stability. Finally, the modified sensor has been successfully applied for the detection of PCT in tablet formulation and human serum samples.