One-pot engineering of novel cashew like cobalt tungstate; dynamic electrocatalyst for the selective detection of promethazine hydrochloride

Determination of promethazine in forensic samples using multi-walled carbon nanotube-gold nanoparticle electrochemical sensor

An electrochemical sensor was developed based on a glassy carbon electrode (GCE) modified with multi-walled carbon nanotubes (MWCNTs) and gold nanoparticles (AuNPs) for the determination of promethazine (PMZ) in 'purple drank', pharmaceutical formulations, and synthetic saliva. The oxidation of PMZ at the modified electrode occurred at a higher cathodic potential and produced a higher sensitivity compared to the unmodified GCE. The morphology of the modified electrode was characterized using field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and transmission electron microscopy (TEM). The presence of MWCNTs and AuNPs was confirmed. The optimized parameters included the concentration and pH of the supporting electrolyte, amount of modifiers used to fabricate the electrode, deposition potential, and time. Using these optimized conditions, the method has a linear range from 0.5 to 100 μmol L-1, with a R2 value of 0.9991. The limit of detection (3SDblank/slope) was 0.13 μmol L-1. The proposed electrochemical sensor was successfully applied for the determination of PMZ in 'purple drank', pharmaceutical formulations, and spiked synthetic saliva samples. The results obtained from this sensor were in statistical agreement with the values obtained using the reference gas chromatography-flame ionization method.

CdO Decorated with Polypyrrole Nanotube Heterostructure: Potent Electrocatalyst for the Detection of Antihistamine Drug Promethazine Hydrochloride in Environmental Samples

In the realm of electrochemical sensor application, the development and fabrication of semiconducting metal oxides with the integration of conducting polymers for the trace-level detection of pharmaceutical medicines garnered considerable interest. Herein, we reported facile cadmium oxide decorated with polypyrrole nanotubes fabricated on a glassy carbon electrode (CdO@PPy/GCE) for efficient determination of antihistamine drug promethazine hydrochloride (PMH). The as-synthesized CdO@PPy composite was characterized by various analytical tools like X-ray powder diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. Furthermore, the electrocatalytic activity of the modified electrode for PMH detection was examined by voltammetry and amperometric methods, and the modified electrode exhibited lower charge transfer resistance compared to the bare GCE. Under the optimized condition, the fabricated electrode shows a wide linear range (50-550 μM), better sensitivity (0.13 μAμM-1 cm-2), low detection limit (10.83 nM) (S/N = 3), and excellent selectivity and reproducibility toward PMH detection. Moreover, the modified GCE depicted eminent practical ability for PMH detection in lake water and pharmaceutical tablets.

Development of the New Sensor Based on Functionalized Carbon Nanomaterials for Promethazine Hydrochloride Determination

Promethazine hydrochloride (PM) is a widely used drug so its determination is important. Solid-contact potentiometric sensors could be an appropriate solution for that purpose due to their analytical properties. The aim of this research was to develop solid-contact sensor for potentiometric determination of PM. It had a liquid membrane containing hybrid sensing material based on functionalized carbon nanomaterials and PM ions. The membrane composition for the new PM sensor was optimized by varying different membrane plasticizers and the content of the sensing material. The plasticizer was selected based on calculations of Hansen solubility parameters (HSP) and experimental data. The best analytical performances were obtained using a sensor with 2-nitrophenyl phenyl ether (NPPE) as the plasticizer and 4% of the sensing material. It had a Nernstian slope (59.4 mV/decade of activity), a wide working range (6.2 × 10^-7 M-5.0 × 10^-3 M), a low limit of detection (1.5 × 10^-7 M), fast response time (6 s), low signal drift (-1.2 mV/h), and good selectivity. The working pH range of the sensor was between 2 and 7. The new PM sensor was successfully used for accurate PM determination in a pure aqueous PM solution and pharmaceutical products. For that purpose, the Gran method and potentiometric titration were used.