Potentiometric planar platforms modified with a multiwalled carbon nanotube/polyaniline nanocomposite and based on imprinted polymers for erythromycin assessment.

A screen-printed potentiometric sensor for the erythromycin macrolide antibiotic (ERY) that is affordable, highly selective, and sensitive is made, described, and used for drug monitoring. Two circular carbon dots with a diameter of 4 mm make up the sensor. Multiwalled carbon nanotubes and polyaniline (f-MWCNTs/PANi) nanocomposites are used to change one carbon spot, which is then used as an ion-to-electron transfer material. Ag/AgCl is applied to the other spot, which is then used as a reference electrode. A solid-state polyvinyl butyral (PVB) is placed onto the second carbon spot to work as a reference electrode, and an ERY molecularly imprinted drug polymer (MIP) is coated onto the f-MWCNTs/PANi-containing strip to serve as a drug identification sensing material. Chronopotentiometry (CP) is used to analyze the integrated sensor's performance characteristics. It is confirmed that f-MWCNTs/PANi has an increased impact on the potential stability as well as the sensing membrane's interfacial double-layer capacitance. At a detection limit of 9.6 ± 0.4 × 10-7 M, the developed sensor exhibits a Nernstian slope of 54.0 ± 0.5 mV per decade (R2 = 0.9994) over the linear range of 4.6 × 10-6 to 1.0 × 10-3 M. When exposed to different related substances such azithromycin, clarithromycin, dirithromycin, paracetamol, and ascorbic acid, the sensor exhibits excellent selectivity. For the direct potentiometric determination of ERY in some pharmaceutical formulations and in samples of spiked human urine, the assay method has been validated and shown to be adequate. The obtained recovery ranges from 93.0 ± 0.5 to 104.3 ± 0.7 of the nominal or spiked concentration, with a mean relative standard deviation of ±0.6%. Due to the near closeness of the responsive membrane and the liquid junction, the use of all-solid-state electrodes coupled with a planar disposable platform enables applications with a minimum sample volume. The effectiveness of the suggested sensor in a complex urine matrix points to its use in hospitals for quick overdose patient detection as well as for quality control/quality assurance tests in the pharmaceutical sector.

Paper-Based Analytical Device Based on Potentiometric Transduction for Sensitive Determination of Phenobarbital.

In medicine, barbiturates are a class of depressive medications used as hypnotics, anticonvulsants, and anxiolytics. For the treatment of specific forms of epilepsy and seizures in young children in underdeveloped countries, the World Health Organization recommends phenobarbital (PBAR), a barbiturate drug. This review describes the fabrication and characterization of a paper-based analytical apparatus for phenobarbital detection that is straightforward, affordable, portable, and disposable. All of the solid-state ion-selective electrodes (ISEs) for PBAR as well as a Ag/AgCl reference electrode were constructed and optimized on a nonconductive paper substrate. Using carbon nanotube ink, the sensors were made to function as an ion-to-electron transducer and to make the paper conductive. A suitable polymeric membrane is drop-cast onto the surface of the carbon ink orifice. The pyrido-tetrapeptide and pyrido-hexapeptide derivatives, which were recently synthesized, functioned as distinct ionophores in the PBAR-membrane sensor, enabling its detection. With a detection limit of 5.0 × 10-7 M, the manufactured analytical device demonstrated a Nernstian response to PBAR anions in 50 mM phosphate buffer, pH 8.5, over a linear range of 1.0 × 10-6 to 1.0 × 10-3 M. The PBAR-based sensors showed quick (less than 5 s) response times for PBAR ion detection. The modified separate solution method was utilized to evaluate the selectivity pattern of these novel ionophores with respect to PBAR ions in comparison to other common anions. The analytical instrument that was exhibited on paper had good precision both within and between days. The suggested technology assisted in the detection of trace amounts of PBAR in real pharmaceutical samples. A comparison was made between the data acquired using the HPLC reference method and the information obtained by the recommended potentiometric approach. The described paper-based analytical device may be a good choice for point-of-care PBAR determination because it is cheap and easy to find and can self-pump (especially when combined with potentiometric detection).

Point-of-care paper-based analytical device for potentiometric detection of myoglobin as a cardiovascular disease biomarker.

One of the cardiac biomarkers, myoglobin (Mb), is important in the rapid identification of cardio-vascular disorders. Therefore, point-of-care monitoring is essential. Pursuing this goal, a robust, reliable, and affordable paper-based analytical apparatus for potentiometric sensing has been developed and characterized. The molecular imprint technique was used to create a customized biomimetic antibody for myoglobin (Mb) on the surface of carboxylated multiwalled carbon nanotubes (MWCNT-COOH). This was accomplished by attaching Mb to carboxylated MWCNTs' surfaces and then filling the empty spaces through the mild polymerization of acrylamide in N,N-methylenebisacrylamide and ammonium persulphate. The modification of the MWCNTs' surface was verified by SEM and FTIR analysis. A hydrophobic paper substrate coated with fluorinated alkyl silane (CF3(CF2)7CH2CH2SiCl3, CF10) has been coupled with a printed all-solid-state Ag/AgCl reference electrode. The presented sensors showed a linear range of 5.0 × 10-8 to 1.0 × 10-4 M with a potentiometric slope of -57.1 ± 0.3 mV decade-1 (R2 = 0.9998) and a detection limit of 28 nM at pH 4. Compared to creatinine, sucrose, fructose, galactose, sodium glutamate, thiamine, alanine, ammonium, uric acid, albumin, glutamine, guanine, troponine T, and glucose, the sensor showed good selectivity for Mb. It demonstrated a good recovery for the detection of Mb in several fake serum samples (93.0-103.3%), with an average relative standard deviation of 4.5%. The current approach might be viewed as a potentially fruitful analytical tool for obtaining disposable, cost-effective paper-based potentiometric sensing devices. These types of analytical devices can be potentially manufacturable at large scales in clinical analysis.

Synthesis, cytotoxic evaluation, and molecular docking studies of novel quinazoline derivatives with benzenesulfonamide and anilide tails: Dual inhibitors of EGFR/HER2.

We synthesized a new series of 2-[(3-(4-sulfamoylphenethyl)-4(3H)-quinazolinon-2-yl)thio]anilide derivatives (2-16) and evaluated their cytotoxic activity against breast adenocarcinoma (MCF-7), colorectal adenocarcinoma (HT-29), and acute myeloid leukemia (HL-60 and K562) cells. To reveal their selectivity toward cancer cells, the compounds were also tested against the human fibroblast cell line, MRC-5. Compounds 1-5 exhibited potent cytotoxic activity against the tested cell lines with IC50 values of 0.65-3.86, 0.68-4.60, 0.41-1.45, 0.42-4.07, and 3.77-25.55 µM, respectively compared to sorafenib, the standard drug (IC50 2.50, 2.50, and 3.14 µM against MCF-7, HT-29, and HL60 cells, respectively). Interestingly, compounds 1-5 displayed selectivity toward the cancer cell lines over MRC-5 (IC50 3.77-25.55 µM). These compounds also displayed potent inhibitory activity against EGFR and HER2 kinases (IC50 0.09-0.43 and 0.15-0.33 µM, respectively) compared to the standard drug, sorafenib (IC50 0.11 and 0.13 µM, respectively). Likewise, compounds 1, 4, and 5 showed strong inhibitory activity against VEGFR2 (IC50 0.34, 0.28 and 0.39 µM, respectively) compared to sorafenib (IC50 0.17 µM). We also employed molecular docking to identify the structural features required for the EGFR/HER2 inhibitory activity of the new series. Ultimately, compounds 1, 4, and 5 were demonstrated to be candidates for further preclinical investigations.

Synthesis, anticancer, apoptosis-inducing activities and EGFR and VEGFR2 assay mechanistic studies of 5,5-diphenylimidazolidine-2,4-dione derivatives: Molecular docking studies.

A new series of 5,5-diphenylhydantoin derivatives containing benzylidene or isatin (4-19) was synthesized. Their anticancer activity against HeLa, a cervical cancer cell line, A549, a lung cancer cell line, and MDA-MB-231, a breast cancer cell line, was evaluated. Compounds 13, 16, 17 and 18 exhibited potent anticancer activity with average IC50 values against the tested cell lines of 109, 59, 81 and 113 µM, respectively. Compound 16 showed potent EGFR and VEGFR2 inhibitory activity with IC50 values of 6.17 and 0.09 µM, respectively. In addition, compound 16 induced caspase-dependent apoptosis and reactive oxygen species (ROS) production at 5 and 10 µM. Moreover, a molecular docking simulation was performed for compound 16 and sunitinib to predict the protein-ligand interactions with the active site of VEGFR2.