Ternary Metal\n(W–Ni–Sr) Oxide@Polypyrrole\nNanotubes: A New Frontier in the Electrochemical Detection of Promethazine\nHydrochloride (PMHC)

Promethazine hydrochloride (PMHC) is a vital drug that\nis used\nas an anticholinergic, antipsychotic, antihistaminic, analgesic, sedative,\nand neuroleptic. However, the overdosage of PMHC also causes reproductive\nvariations, cardiac changes, hypotension, and endocrinal variations.\nHence, the detection of PMHC is crucial. Therefore, in this work an\nelectrochemical method for the detection of PMHC is reported. The\nfabrication for the modified electrode is built with tungsten (W),\nnickel (N), and strontium (S) ternary oxide (tWNSO). To the best of\nour knowledge, this tWNSO ternary oxide preparation is reported for\nthe first time in the literature. The prepared ternary oxide is deposited\non the polypyrrole nanotubes, and this nanocomposite that is formed\nis confirmed by various physical characterizations like XRD, SEM,\nTEM, UV–vis spectroscopy, FTIR spectroscopy, and also DFT studies\nfor PMHC. Thus, the nanocomposite obtained is used as a working electrode\nfor the detection of PMHC. The fabricated tWNSO/PPyNTs/GCE has an\neffective surface area of 0.0436 cm<sup>2</sup>. Also, no fouling\nwas observed. The limit of detection of the analyte PMHC is 3.66 nM,\nthe limit of quantification is 11.10 nM, and the sensitivity of the\nfabricated electrode in identifying the analyte is found to be 20.10\nμA μM<sup>–1</sup> cm<sup>–2</sup>. Thus,\nthe modified working electrode effectively detects the analyte PMHC\nwhile demonstrating excellent stability and reproducibility.