Publications by authors named "Mahmoud El-Maghrabey"

In the current study, the triazole antifungal terconazole (TRZ) was determined using a novel, extremely sensitive, and environmentally friendly spectrofluorimetric approach. A methanolic solution of TRZ exhibited strong native fluorescence at 373 nm when excited at 241 nm. With a correlation coefficient of 0.

View Article and Find Full Text PDF

Tyrosinase is an enzyme that metabolizes L-tyrosine and is found in various organisms. Its overactivity can lead to health issues in humans, such as hyperpigmentation, and can adversely affect human skin, leading to skin cancers. This has heightened the significance of tyrosinase inhibitors in pharmaceuticals and cosmetics, particularly skin-whitening formulations.

View Article and Find Full Text PDF

Metronidazole (MTZ) and nicotinamide (NCT) are co-formulated in Anaero® gel to treat skin conditions like acne and rosacea through combined antimicrobial and anti-inflammatory effects. This study presents the first validated in vitro permeation test (IVPT) method using Franz cells to assess the gel's drug release profile. Chromatographic separations were conducted with an RP-HPLC-photodiode array (PDA) system equipped with an ODS column using gradient elution of ethanol and phosphate buffer (10 mM, pH 3.

View Article and Find Full Text PDF

This study presents a very sensitive and eco-friendly synchronous spectrofluorimetric method for the simultaneous quantification of propofol (PRP) and nalbuphine (NAL) for the first time. The technique used the intrinsic fluorescence characteristics of the two drugs, providing enhanced sensitivity and specificity. The two drugs were assessed simultaneously at 217 nm and 281 nm for PRP and NAL, respectively, with a synchronous wavelength difference (Δλ) of 80 nm.

View Article and Find Full Text PDF

This study seeks to develop and implement a non-enzymatic fluorescent labeling for immunoassay and immunochromatographic assay (ICAs) targeting SARS-CoV-2, to meet the extensive interest and need for effective COVID-19 diagnosis. In this manuscript, we delineate the development, synthesis, and evaluation of a novel quinone polymer zinc hybrid nanoarchitecture, referred to as polymerized alizarin red-inorganic hybrid nanoarchitecture (PARIHN), which integrates an antibody for direct use in fluorescent immunoassays, offering enhanced sensitivity, reduced costs, and improved environmental sustainability. The designed nanoarchitecture can enhance the sensitivity of the immunoassay and enable rapid results without the complexities associated with enzymes, such as their low stability and high cost.

View Article and Find Full Text PDF

Background: The current synthetic strategies for carbon dots (CDs) are usually time-consuming, rely on complicated processes, and need high temperatures and energy. Recent studies have successfully synthesized CDs at room temperature. Unfortunately, most CDs synthesized at room temperature are obtained under harsh reaction conditions, prepared using aromatic precursors, or need a long time to generate.

View Article and Find Full Text PDF

The current study introduces the first micellar-enhanced spectrofluorimetric approach for the estimation of the commonly abused CNS antitussive, dextromethorphan (DXM) in its syrup and biological fluids. A micellar solution of sodium dodecyl sulfate (SDS) containing DXM showed high native fluorescence emission at 305 nm following excitation at 224 nm. Using SDS as a micellar system resulted in about a 2.

View Article and Find Full Text PDF

Herein, we developed a colorimetric method for the determination of Cu and Zn using NBD-G as a novel selective metal sensor. NBD-G was easily synthesized by a nucleophilic substitution reaction between 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) and Girard's Reagent P. The NBD-G solution is yellow, but when it reacts with Cu and Zn, its color changes selectively to red (510 nm) and orange (480 nm), respectively.

View Article and Find Full Text PDF

Hypertension is the predominant risk factor for cardiovascular diseases and mortality. This study presents the first method for the simultaneous analysis of the co-administered antihypertensive drugs, Carvedilol (CAR) and Telmisartan (TEL) using a fast, highly sensitive, environmentally friendly, and cost-effective second derivative synchronous spectrofluorimetric approach. The fluorescence of CAR and TEL was quantified at 243 nm and 274.

View Article and Find Full Text PDF

This work introduces an extremely easy method for preparing luminescent carbon dots (CDs) at ambient temperature using 1,2-naphthoquinone sulphonate and ethylenediamine as precursors via self-exothermic reaction without energy input. The as-obtained CDs have a high quantum yield (34.1 %), a production yield of 21.

View Article and Find Full Text PDF

This research addresses the challenge of analyzing pregabalin, a primary amine in a zwitterionic structure, which is difficult to evaluate due to its lack of chromatophore. The study introduces a derivatization assessment using Hantzsch's multicomponent organic reaction to enhance the detectability of pregabalin by forming a highly fluorescent dihydropyridine derivative. This process involves the condensation of pregabalin with acetylacetone and formaldehyde, yielding a yellowish-green compound measurable both colorimetrically at 338 nm and fluorimetrically at an emission wavelength of 486 nm (λ = 408 nm).

View Article and Find Full Text PDF

This contribution aims to design and validate a new green, cheap, and fast approach for determining the anti-GERD drug pantoprazole in different matrices. New S and N-doped carbon nanomaterials (S,N-CNMs) have been prepared via microwave irradiation of a mixture of widely available household sources. Remarkably, the utilization of a blend of carbamide and thiocarbamide with table sugar yields S,N-CNMs exhibiting the utmost quantum yield (54 %), hydrophilicity, as well as stable, homogeneous, and diminutive particle size distribution.

View Article and Find Full Text PDF

Background: Nitroxinil has been used extensively to treat parasitic worms, mainly Fasciola, in food-producing cattle and sheep. The reported methods for nitroxinil analysis included expensive instrumentation, the need for skilled operators, and tedious procedures. Fluorimetry is one of the fastest and simplest methods widely used; hence, we aimed to develop a simple, cost-effective, and convenient fluorometric approach for the estimation of nitroxinil in various matrices.

View Article and Find Full Text PDF

Green and efficient agro-waste-based activated carbon has been prepared utilizing peanut shells for adsorptive elimination of an industrial dye, methylene blue, and lead from polluted water. The carbonaceous biomass obtained from peanut shells was chemically activated using either NaOH, ZnCl, or steam and characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and N adsorption and desorption studies. The adsorption process was optimal for methylene blue at alkaline pH, while pH 4.

View Article and Find Full Text PDF

Background: L-p-Boronophehylalanine (BPA) is used in boron neutron capture therapy (BNCT), which is a novel selective cancer radiotherapy technique. It is important to measure BPA levels in human blood for effective radiotherapy; a prompt gamma-ray spectrometer, ICP-AES, and ICP-MS have been used for this purpose. However, these methods require sophisticated and expensive apparatuses as well as experienced analysts.

View Article and Find Full Text PDF

Letrozole is an anticancer medication prescribed for the management of estrogen receptor-positive breast cancer in postmenopausal women. Chronic pain is prevalent in patients receiving chemotherapy, leading to the use of adjuvant analgesics such as tramadol. This work introduces the first analytical approach for the concurrent quantification of letrozole and tramadol, two co-administered drugs, employing a rapid, highly sensitive, eco-friendly, and cost-effective first derivative synchronous spectrofluorimetric technique.

View Article and Find Full Text PDF

Herein, we developed a rapid, one-step, and cost-effective methodology based on the fabrication of water-soluble self-nitrogen, sulfur, and phosphorus co-doped black seed carbon quantum dots (BSQDs) via microwaveirradiation in six minutes. Our synthesis approach is superior to those in the literature as they involved long-time heating (12 h) with sulfuric acid and sodium hydroxide and/or high temperatures (200 °C). A full factorial design was applied to obtain the most efficient synthesis conditions.

View Article and Find Full Text PDF

Palladium-catalyzed coupling reactions are versatile and powerful tools for the construction of carbon-carbon bonds in organic synthesis. Although these reactions have favorable features that proceed selectively in mild reaction conditions using aqueous organic solvents, no attention has been given to their application in the field of biomedical analysis. Therefore, we focused on these reactions and evaluated the scope and limitations of their analytical performance.

View Article and Find Full Text PDF

Vanillin is a flavouring agent that is prohibited for use in infant food products with ages lower than 6 months. Excessive vanillin usage could lead to eating disorders, nausea, headache, and vomiting. Therefore, it is essential to control the contents of vanillin in food samples, especially in infant formula.

View Article and Find Full Text PDF

The current study designed and applied a novel self-ratiometric fluorescent nanosensor composed of green-synthesized silver nanoparticles (Ag-NPs) to determine vanillin in adult and infant foods and human plasma. A straightforward microwave-assisted approach is proposed for synthesizing Ag-NPs in less than 1 min using a reducing agent, tailed pepper seed extract. The synthesized Ag-NPs had a strong fluorescence with an intense emission band at 360 nm and a shoulder peak at 430 nm when excited at 265 nm.

View Article and Find Full Text PDF

Biotin, or vitamin B7, is essential for metabolic reactions. It must be obtained from external sources such as food and biotin/vitamin supplements because it is not biosynthesized by mammals. Therefore, there is a need to monitor its levels in supplements.

View Article and Find Full Text PDF

In this study, the simultaneous determination of bilastine and montelukast, two recently approved co-formulated antihistaminic medications, was accomplished using a quick, sensitive, environmentally friendly, and reasonably priced synchronous fluorescence spectroscopic approach for the first time. Enhancement of the method's sensitivity down to nanogram levels was achieved by the addition of sodium dodecyl sulfate (1.0% w/v) as a micellar system.

View Article and Find Full Text PDF

Nuclear receptors (NRs) constitute a superfamily of ligand-activated transcription factors with a paramount role in ubiquitous physiological functions such as metabolism, growth, and reproduction. Owing to their physiological role and druggability, NRs are deemed attractive and valid targets for medicinal chemists. Pentacyclic triterpenes (PTs) represent one of the most important phytochemical classes present in higher plants, where oleanolic acid (OA) is the most studied PTs representative owing to its multitude of biological activities against cancer, inflammation, diabetes, and liver injury.

View Article and Find Full Text PDF

Green, one-pot, quick, and easily synthesized nitrogen and sulfur co-doped carbon quantum dots (N,S-CDs) were obtained from cheap and readily available chemicals (sucrose, urea, and thiourea) using a microwave-assisted approach in about 4 min and utilized as a turn-off fluorescent sensor for estimation of natamycin (NAT). First, the effect of N and S doping on the microwave-synthesized CDs' quantum yield was carefully studied. CDs derived from sucrose alone failed to produce a high quantum yield; then, to increase the quantum yield, doping with heteroatoms was carried out using either urea or thiourea.

View Article and Find Full Text PDF

A simple, fast, and direct mix-and-read spectrofluorimetric method has been developed for the sensitive determination of naftazone (NFZ) utilizing graphene quantum dots (GQDs) as a greener and highly luminescent nanosensor. NFZ effectively quenches the strong fluorescence of GQDs at λ/λ of 350/440 nm via the inner filter effect mechanism. The nanosensor exhibits excellent linearity for NFZ over the concentration range of 0.

View Article and Find Full Text PDF