All-Solid-State Potentiometric Ion-Sensors Based on Tailored Imprinted Polymers for Pholcodine Determination

Abstract

In recent times, the application of the use of ion-selective electrodes has expanded in the field of pharmaceutical analyses due to their distinction from other sensors in their high selectivity and low cost of measurement, in addition to their high measurement sensitivity. Cost-effective, reliable, and robust all-solid-state potentiometric selective electrodes were designed, characterized, and successfully used for pholcodine determination. The design of the sensor device was based on the use of a screen-printed electrode modified with multiwalled carbon nanotubes (MWCNTs) as a solid-contact transducer. Tailored pholcodine (PHO) molecularly imprinted polymers (MIPs) were prepared, characterized, and used as sensory receptors in the presented potentiometric sensing devices. The sensors exhibited a sensitivity of 31.6 ± 0.5 mV/decade (n = 5, R2 = 0.9980) over the linear range of 5.5 × 10−6 M with a detection limit of 2.5 × 10−7 M. Real serum samples in addition to pharmaceutical formulations containing PHO were analyzed, and the results were compared with those obtained by the conventional standard liquid chromatographic approach. The presented analytical device showed an outstanding efficiency for fast, direct, and low-cost assessment of pholcodine levels in different matrices.

Determination of pholcodine alone or in combination with ephedrine in human plasma using fluorescence spectroscopy

“…In Egypt, PHL is classified as a substance subject to drug restrictions according to Table 3 attached to the Egyptian Drug Law No. 182 of 1960 5 . The European Medicines Agency (EMA) has recently updated its comprehensive benefit/risk analysis 6 .…”

“…Variable methods for determination of PHL have been reported including UV/Vis spectrophotometry 9 , spectrofluorimetry 10 , high-performance liquid chromatography (HPLC) 11 – 14 , gas chromatography (GC) 15 , chemiluminescence 16 , non-aqueous titration 17 , and electrochemistry 5 , 18 . Similarly, EPH was determined using spectrophotometric methods 19 – 22 , HPLC 23 – 25 , capillary electrophoresis 26 – 29 , GC 30 , 31 , LC-MS 30 , 32 , 33 , and electrochemistry 34 , 35 .…”

Exploiting the power of UPLC in separation and simultaneous determination of pholcodine, guaiacol along with three specified guaiacol impurities

“…PHL is an official drug in the British Pharmacopoeia (BP) in which a non-aqueous titration technique is described for its assay [ 1 ]. On the reviewing literature of the last decade, PHL was determined either in a single form or combined with other drugs by several methods, namely; UV spectrophotometric [ 2 , 3 ], infrared spectroscopic [ 4 ], fluorimetric [ 5 , 6 ], chromatographic [ 7 – 9 ] and potentiometric [ 10 , 11 ] ones.…”

An all-solid-state potentiometric microsensor for real-time monitoring of the calcification process byBacillus subtilisbiofilms

“…15,16 Carbon nanotubes with inherent hydrophobicity, good electrical conductivity, and a certain specific capacitance have been used as ion-to-electron transduction layers 17,18 in solid-state ion-selective electrodes for anions, 19,20 cations, 18,21 and small molecules. 22 Primitive and functionalized carbon nanotubes can not only eliminate the unwanted water layer between the ion-selective membrane and the electrode substrate but also show significant advantages in terms of ion-to-electron transduction. 23 In recent years, fibers of aligned CNTs that can well preserve the characteristics of individual CNTs have been prepared and utilized as electrode materials in many areas, such as electronics, energy storage, and health care.…”