Fabrication of an Electrochemical Sensor Based upon Polyphenylenediamine/MWCNTs Nano-Composite for the Determination of Morphine

In the present study, a morphine sensor based upon Molecularly Imprinted Polymer (MIP) composed of polyphenylenediamine, multi-walled carbon nanotube, and triphenylamine has been synthesized. The synthesized MIP was characterized using the conventional techniques of Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX) spectroscopy, Fourier Transform InfraRed (FT-IR) spectroscopy, and electrochemical methods. Incorporation of the prepared MIP, as a selective sensory material, in the carbon paste resulted in the fabrication of a morphine-selective electrochemical sensor. The developed sensor was utilized as an indicator electrode in the cyclic voltammetry technique to optimize the parameters affecting the sensor's potential for morphine detection. The sensor displayed linear anodic peak current responses as a function of the morphine concentration in the range 1.0-1.5×103 mg/L (LOD and actual LOD were found to be 0.24 and 0.48 mg/L, respectively). Its reproducibility was screened by evaluating inter- and intra-day relative standard deviations, which were 1.57% and 2.09%, respectively. The selectivity of the sensor toward morphine was evaluated by determining the analyte in the presence of potential interfering compounds, including glucose, ascorbic acid, urea, thebaine, and codeine. The accurate quantification of morphine in real samples underscores the developed sensor’s ability as a reliable for such measurements.