A novel screen-printed potentiometric electrode with carbon nanotubes/polyaniline transducer and molecularly imprinted polymer for the determination of nalbuphine in pharmaceuticals and biological fluids

A novel screen-printed electrode (SPE) for potentiometric determination of nalbuphine (NAL) is described. Carboxylated multi-walled carbon nano tubes/polyaniline (f-MWCNTs/PANI) nanocomposite is used as an ion- to-electron transducer and is covered by a selective polyvinyl chloride (PVC) membrane incorporated with molecularly imprinted drug polymer (MIP) beads as a recognition receptor for potentiometric determination a synthetic narcotic, nalbuphine (NAL). The SPE displays a Nernstian response with a slope of 60.3 +/- 1.2 mV/ decade (R-2 = 0.999) over the concentration range 2.4 x 10(-7) - 5.0 x 10(-2) mol/L and a detection limit of 1.1 x 10(-7 )mol/L (0.04 mu g/mL) with response time less than 20 s (< 20 s). The interfacial capacitance of the proposed SPE is measured using chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS). The use of the f-MWCNTs/PANI nanocomposite layer improved the interfacial capacitance reached 52.5 mu F. Besides, it eliminated the formation of the undesired thin water-layer between the sensing membrane and the conducting substrate. This prevents membrane delamination and increases potential stability. The obtained high selectivity, sensitivity and potential stability offered a great applicability of the proposed SPE for the determination of nalbuphine in hospitals for rapid diagnosis of overdose patients and for quality control/quality assurance in pharmaceutical industry.

Automated summary

A novel screen-printed electrode (SPE) is developed for the potentiometric determination of nalbuphine, a synthetic narcotic. The electrode utilizes a carboxylated multi-walled carbon nano tubes/polyaniline nanocomposite as an ion-to-electron transducer, covered by a selective polyvinyl chloride membrane incorporated with molecularly imprinted drug polymer beads. The SPE exhibits excellent sensitivity, selectivity, and potential stability, making it suitable for rapid diagnosis of overdose patients in hospitals and quality control/quality assurance in the pharmaceutical industry.