Ultrasensitive green spectrofluorimetric approach for quantification of Hg(II) in environmental samples (water and fish samples) using cysteine@MnO2 dots

Preparation and application of a new ion-imprinted polymer for nanomolar detection of mercury(II) in environmental waters

This study introduces a novel ion-imprinted polymer for the ultrasensitive detection of mercury(II) in water. The ion-imprinted polymer was synthesized via a simple bulk polymerization process using methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, morpholine-4-carbodithioic acid phenyl ester as the chelating agent, and ammonium persulfate as the initiator. The electrochemical mercury(II) sensing capability of the ion-imprinted polymer was studied via the modification of a cost-effective carbon paste electrode. A stripping voltammetric technique was utilized to quantify the analyte ions following open-circuit enrichment. Critical experimental parameters, including the nature and concentration of the eluent, solution pH, preconcentration duration, ion-imprinted polymer dosage, sample solution volume and reduction potential, were systematically studied and optimized. Under optimal conditions, the sensor exhibited a linear response in the range of 1.0 to 240.0 nM, with a low detection limit of 0.2 nM. The sensor demonstrated remarkable selectivity against potential interfering ions, including lead(II), cadmium(II), copper(II), zinc(II), manganese(II), iron(II), magnesium(II), calcium(II), sodium(I) and cobalt(II). The practical applicability of the developed method was successfully validated through the analysis of real water samples, suggesting its potential for environmental monitoring applications.

Design of new boron-doped carbon dots for nano-level assay of nebivolol in human plasma and commercial products; Application to greenness assessments

Recently, nanomaterials have attracted a lot of attention due to their potential as effective fluorescent nano-sensor probes. They were distinguishing substitutes for other luminescent techniques, such as fluorescent dyes and luminous derivatization, because of their affordability, environmental friendliness, and special photocatalytic properties. In the suggested work, a straightforward method was used to create boron and nitrogen carbon dots (B@CDs) with a good quantum yield value of 31.15 % utilizing boric acid and di-sodium EDTA. For the purpose of characterizing QDs, a variety of instruments were employed, such as transmission electron microscopy, fluorescence spectroscopy, X-ray FTIR, and UV-VIS spectroscopy. Nebivolol (NEB) is a cardiovascular medication used globally to treat congestive heart failure and hypertension, is in the meantime. For this reason, a brand-new, environmentally friendly analytical technique was created to determine the amount of human plasma, uniformity test, and commercial nebivolol (NEB) tablets. After gradually adding NEB, the response of B@CQDs was enhanced at 438 nm (excitation at 371 nm). The calibration graph ranged between 20 and 500 ng mL-1 with a quantification limit (LOQ) of 2.50 ng mL-1 and a detection limit (LOD) of 0.82 ng mL-1.

Electrochemical and computational evaluation of hydrazide derivative for mild steel corrosion inhibition and anticancer study

In the present study the authors' main goal is to avoid the corrosive attack of the chloride ions of 3.5% NaCl solution in saline medium on the mild steel (MS), by addition of small amount of a new derivative of the hydrazide called ligand (HL), as a corrosion inhibitor. This study had been achieved by employing different electrochemical measurements such as, open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentio-dynamic polarization (PDP) methods. The results of the electrochemical test (OCP), showed that, the open circuit potential of the mild steel in saline solution, was guided to more positive direction in presence of the ligand (HL), at its ideal concentration (1 × 10-3 M), compared to the (OCP), of the mild steel in absence of (HL). The results of the electrochemical methods, EIS and PDP presented that, the ligand (HL), was acted as a good corrosion inhibitor for hindering the corrosion process of the mild steel in 3.5% sodium chloride, as it was recorded a good percentage of the inhibition efficiency (77.45%, 53.41%, by EIS and PDP techniques respectively), at its optimum concentration (1 × 10-3 M). Also, the corrosion rate of the mild steel in the saline medium without (HL), was listed about (0.0017 mm/year), while in existence of (HL), was decreased to a value about (0.00061 mm/year). As well, some of electrical properties of (HL), and its derivative [Pd(II), Cr(III), and Ru(III)], complexes were investigated such as; the activation energy (Ea(ac)), which recorded values in the range of 0.02-0.44 (eV) range and electrical conductivity which listed values at room temperature in the range of 10-5-10-8 S.cm-1. The results of the AC and DC electrical conductivity measurements for (HL), and its derivative [Pd(II), Cr(III) and Ru(III)] complexes indicate semiconducting nature which suggests that these compounds could be used in electronic devices. Also, the complexes exhibited higher conductivity values than (HL). Photophysical studies showed good florescence properties of HL that indicated that it can be used to determine most of the drugs with no fluorescence properties by quenching and calculating quantum yield. Moreover, the hydrazide ligand (HL), has shown selectivity as an active anticancer candidate drug for both breast and colon cancer in humans. Density function theory demonstrated that, the frontier molecular orbital HOMOs of the complexes have exhibited similar behavior and the charge density has localized in the metallic region of all the studied complexes. Also, the values of the energy gap of the ligand (HL), and its complexes Pd(II), Cr(III) and Ru(III), had been arranged in this order HL > Cr(III) > Ru(III) > Pd(II). All characterization using different spectroscopic techniques were reported to elucidate the proposed structures such as; thermal analysis, elemental analysis of C, H, and N atoms, spectral analysis using IR, UV, 1H NMR techniques, scanning electron microscopy and energy dispersive X-ray analyses.

Synthesis of organic solvent-free nitrogen-doped carbon quantum dots as unique green fluorimetric probes for analysis of abrocitinib in human plasma

Atopic dermatitis (AD) is a persistent, inflammatory skin condition that impacts approximately 15 to 20% of children and 1 to 3% of adults globally. Common skin manifestations include papules, papulovesicular, and brown or red patches with swelling, crusting, and flaking. Therefore, the drug abrocitinib (ABR) was approved by the US FDA as an oral treatment for atopic dermatitis. The present study outlines the development of innovative, thermostable, and pH-stable organic solvent-free nitrogen-doped carbon dots (N@CQDs) synthesized through a one-step method for evaluating ABR with a notable quantum yield of 33.84% to minimize the use of organic solvents. Their cost-effectiveness, eco-friendly characteristics, and outstanding photocatalytic properties have established them as a promising alternative to conventional luminescent techniques like fluorescent dyes and luminous derivatization technique. The reaction of ABR with N@CQDs led to a significant decrease in the luminescent response of the produced green and stable carbon quantum dots at 513 nm. The detection range was determined to be 1.0-150.0 ng mL-1, with a lower limit of quantitation (LOQ) equal to 0.52 ng mL-1 based on the linear graph. The green method effectively used for analysis of ABR in pharmaceutical tablets and pharmacokinetic study with high sensitivity.

Potential in-vitro antioxidant and anti-inflammatory activity of Martynia annua extract mediated Phytosynthesis of MnO2 nanoparticles

The present research work describes the phyto-synthesis of Manganese dioxide nanoparticles (MnO2NPs) from the reduction of potassium permanganate using Martynia annua (M.annua) plant extract. From the literature review, we clearly understood the M.annua plant has anti-inflammatory activity. Manganese dioxides are important materials due to their wide range of applications. Their increased surface area gives them distinct capabilities, as it increases their mechanical, magnetic, optical, and catalytic qualities, allowing them to be used in more pharmaceutical applications. A detailed review of literature highlighting the issues related to this present work and its knowledge gap that none of the inflammatory activities had been done by MnO2 NPs synthesized from M.annua plant extract. So we selected this study. The product MnO2 NPs showed the wavelength centre at 370 nm and was monitored by UV-Vis spectra. The wave number around 600 cm-1 has to the occurrence of O-Mn-O bonds of pure MnO2 confirmed by FTIR spectroscopy. Transmission electron microscopy images showed the morphology of MnO2 NPs as spherical-shaped particles with average sizes at 7.5 nm. The selected area electron diffraction analysis exhibits the crystalline nature of MnO2 NPs. The obtained MnO2 NPs showed potential antioxidant and anti-inflammatory activity was compared to the plant extract. The synthesized MnO2 NPs have a large number of potential applications in the field of pharmaceutical industries. In the future, we isolate the phytocompounds present in the M.annua plant extract and conduct a study against corona virus. MnO2 produces manganese (III) oxide and oxygen, which increases fire hazard. But further research is required to understand their environmental behaviour and safety.

Isoquinoline-based intrinsic fluorescence assessment of erythropoiesis-stimulating agent, Roxadustat (FG-4592), in tablets: applications to content uniformity and human plasma evaluation

In the present study, a first validated and green spectrofluorimetric approach for its assessment and evaluation in different matrices was investigated. After using an excitation wavelength of 345 nm, Roxadustat (ROX) demonstrates a highly native fluorescence at an emission of 410 nm. The influences of experimental factors such as pH, diluting solvents, and different organized media were tested, and the most appropriate solvent choice was ethanol. It was confirmed that there was a linear relationship between the concentration of ROX and the relative fluorescence intensity in the range 60.0-1000.0 ng ml-1, with the limit of detection and limit of quantitation, respectively, being 17.0 and 53.0 ng ml-1. The mean recoveries % [±standard deviation (SD), n = 5] for pharmaceutical preparations were 100.11% ± 2.24%, whereas for plasma samples, they were 100.08 ± 1.08% (±SD, n = 5). The results obtained after the application of four greenness criteria, Analytical Eco-Scale metric, NEMI, GAPI, and AGREE metric, confirmed its eco-friendliness. In addition, the whiteness meter (RGB12) confirmed its level of sustainability. The International Council for Harmonisation (ICH) criteria were used to verify the developed method through the study in both spiked plasma samples and content uniformity evaluation. An appropriate standard for various applications in industry and quality control laboratories was developed.

An Innovative Selective Fluorescence Sensor for Quantification of Hazardous Food Colorant Allura Red in Beverages Using Nitrogen-Doped Carbon Quantum Dots

An innovative simple, sensitive, and selective method has been developed and validated for quantification of hazardous Allura red (AR, E129) dye in beverages. Allura red (AR) is a synthetic dye that is commonly used in the food industry to give foods a bright and appealing color. The method is based on microwave-assistant nitrogen-doped carbon quantum dots (N@CQDs) from a very cheap source with a high quantum yield equal to (36.60%). The mechanism of the reaction is based on an ion-pair association complex between AR and nitrogen-doped carbon quantum dots (N@CQDs) at pH 3.2. The reaction between AR and N@CQDs led to a quenching effect of the fluorescence intensity of N@CQDs at 445 nm after excitation at 350 nm. Moreover, the quantum method's linearity covered the range between 0.07 and 10.0 µg mL- 1 with a regression coefficient is 0.9992. The presented work has been validated by ICH criteria. High-resolution transmission electron microscopy (HR-TEM), X-ray photon spectroscopy (XPS), Zeta potential measurements, fluorescence, UV-VIS, and FTIR spectroscopy have all been used to fully characterize of the N@CQDs. The N@CQDs were successfully utilized in different applications (beverages) with high accuracy.

Development of cysteine-doped MnO2 quantum dots for spectrofluorimetric estimation of copper: applications in different matrices

Copper (Cu) plays a role in maintaining healthy nerve cells and the immune system. Osteoporosis is a high-risk factor for Cu deficiency. In the proposed research, unique green, fluorescent cysteine-doped MnO2 quantum dots (Cys@MnO2 QDs) were synthesized and assessed for the determination of Cu in different food and hair samples. The developed quantum dots were synthesized with the help of cysteine using a straightforward ultrasonic approach to create 3D fluorescent Cys@MnO2 QDs. The resulting QDs' morphological and optical characteristics were carefully characterized. By adding Cu ions, the intensity of fluorescence for the produced Cys@MnO2 QDs was found to be dramatically reduced. Additionally, the applicability of Cys@MnO2 QDs as a new luminous nanoprobe was found to be strengthened by the quenching effect grounded on the Cu-S bonding. The concentrations of Cu2+ ions were estimated within the range of 0.06 to 7.00 µg mL-1, with limit of quantitation equal to 33.33 ng mL-1 and detection limit equal to 10.97 ng mL-1. The Cys@MnO2 QD technique was applied successfully for the quantification of Cu in a variety of foods, including chicken meat, turkey, and tinned fish, as well as in human hair samples. The chance that this novel technique could be a useful tool for figuring out the amount of cysteine in bio-samples is increased by the sensing system's remarkable advantages, which include being rapid, simple, and economical.

A Novel Design Eco-friendly Microwave-assisted Cu-N@CQDs Sensor for the Quantification of Eravacycline via Spectrofluorimetric Method; Application to Greenness Assessments, Dosage Form and Biological Samples

Community-acquired pneumonia is one of the most common infectious diseases and a substantial cause of mortality and morbidity worldwide. Therefore eravacycline (ERV) was approved by the FDA in 2018 for the treatment of acute bacterial skin infections, GIT infections, and community-acquired bacterial pneumonia caused by susceptible bacteria. Hence, a green highly sensitive, cost-effective, fast, and selective fluorimetric approach was developed for the estimation of ERV in milk, dosage form, content uniformity, and human plasma. The selective method is based on the utilization of plum juice and copper sulphate for the synthesis of green copper and nitrogen carbon dots (Cu-N@CDs) with high quantum yield. The quantum dots' fluorescence was enhanced after the addition of ERV. The calibration range was found to be in the range 1.0 - 80.0 ng mL-1 with LOQ equal to 0.14 ng mL-1 and LOD was found to be 0.05 ng mL-1. The creative method is simple to deploy in clinical labs and therapeutic drug health monitoring system. The current approach has been bioanalytically validated using US-FDA and validated ICH criteria. High-resolution transmission electron microscopy (HR-TEM), X-ray photon spectroscopy (XPS), Zeta potential measurements, fluorescence, UV-VIS, and FTIR spectroscopy have all been used to fully characterize the Cu-N@CQDs. The Cu-N@CQDs were effectively applied in human plasma and milk samples with a high percentage of recovery ranging from 97.00 to 98.80%.

Applicability of fluorescamine as a fluorogenic reagent for highly sensitive fluorimetric analysis of the tyrosine kinase inhibitor (avapritinib) in pharmaceuticals and biological samples

Avapritinib (AVP) was the first precision drug to be approved by the US Food and Drug Administration (FDA) in 2020 for patients suffering from metastatic gastrointestinal stromal tumors (GISTs) and progressive systemic mastocytosis. The analysis of AVP in pharmaceutical tablets and human plasma was then carried out using a fast, efficient, sensitive, and simple fluorimetric method using a fluorescamine reagent. The procedure is based on the interaction between fluorescamine as a fluorogenic reagent and the primary aliphatic amine moiety in AVP using borate buffer solution at pH 8.8. The produced fluorescence was measured at 465 nm (Excitation at 395 nm). The calibration graph's linearity range was discovered to be 45.00-500.0 ng mL-1 . Utilizing the International Council for Harmonization (ICH) and US-FDA recommendations, the research technique was validated and bioanalytically validated. The proposed approach was effectively employed for determining the stated pharmaceuticals in plasma with a high percentage of recovery ranging from 96.87 to 98.09 and pharmaceutical formulations with a percentage of recovery equal to 102.11% ± 1.05%. In addition, the study was extended to a pharmacokinetic study of AVP with 20 human volunteers as a step for AVP management in therapeutic cancer centers.