Electrochemical sensor based on graphene and tungsten disulfide nanoparticles for determination of noscapine and papaverine

In this research, for the first time, an electrochemical sensor has been introduced by incorporating synthesized graphene nanoparticles (GrNPs) and tungsten disulfide nanoparticles (WS 2 NPs) into a carbon paste (CP) matrix. This sensor was used for the simultaneous measurement of noscapine (NOS) and papaverine (PAP) as two important alkaloids in opium. The properties of the synthesized nanoparticles were examined by scanning electron microscopy, elemental analysis, and X-ray diffraction. The electrochemical behavior of the modified electrode in aqueous solutions was studied by chronoamperometry, cyclic voltammetry, impedance, and differential pulse voltammetry techniques. A significant enhancement in the peak current response of NOS and PAP was observed at the graphene nanoparticles and tungsten disulfide nanoparticle–modified carbon paste electrode (GrNPs/WS 2 NPs/CPE) compared to the bare CPE. Also, using differential pulse voltammetry (DPV) method, linear range 5 to 1000 μM and limit of detection (LOD) (S/N = 3.0) 0.5062 μM and 1.0793 μM were obtained for NOS and PAP, respectively. Real-sample analysis results showed a recovery range 93.0–95.0% and 93.0–95.4 for NOS and PAP, respectively, that confirm a powerful ability of GrNPs/WS 2 NPs/CPE for determination of NOS and PAP in urine and industrial effluent samples.