Hydrothermal synthesis of modified lignin-based carbon dots derived from biomass waste for fluorescence determination of valsartan.

Recently, carbon dots (CDs) have been extensively investigated as potential tools for numerous applications. Modified lignin-based CDs have been synthesized and used in the field of drug detection. They were found to be highly selective and sensitive to valsartan (VAL). Using a simple hydrothermal method, phosphorus and chlorine co-doped CDs were synthesized using lignin extracted from date seeds. The fluorescence properties of the synthesized CDs are influenced by several factors, which were investigated in detail. The optimal synthesis conditions were 1.50 g of lignin, 18 mL of 2 M NaOH, 1 mM H3PO4, 3 mM HCl and the mixture was heated at 220 °C for 16 hours. The synthesized lignin-based CDs have excellent FL properties and are well soluble in water with reasonable stability. Characterization of the prepared CDs revealed that they have various functional groups with a graphene oxide-like structure. The developed CDs show a good quantum yield of 37.7%. The FL of the CDs is quenched by VAL at λ em 313 nm after λ ex at 275 nm by a combination of static and dynamic quenching mechanisms. The response of VAL was linear in the range of 4.0-100.0 µg mL-1. The detection and quantification limits of VAL were 1.23 and 3.71 µg mL-1, respectively. The nanoprobe was successfully used to analyze VAL in drug samples and provided satisfactory results.

Functionalized fennel extract-mediated alumina/cerium oxide nanocomposite potentiometric sensor for the determination of diclofenac sodium medication.

The current work suggests a new, ultrasensitive green functionalized sensor for the determination of anti-inflammatory medication diclofenac sodium (DCF). Alumina (Al2O3) and cerium oxide (CeO2) nanoparticles (NPs) have attracted great interest for their use as outstanding and electroactive nanocomposite in potentiometric and sensory research due to their ultrafunctional potential. The formed nanoparticles have been confirmed using various spectroscopic and microscopic techniques. The fennel extract-mediated Al2O3/CeO2 nanocomposite (Al2O3/CeO2 NCS) modified coated wire membrane sensor developed in this study was used to quantify DCF in bulk and commercial products. Diclofenac sodium was coupled with phosphomolybdic acid (PMA) to generate diclofenac phosphomolybdate (DCF-PM) as an active ion-pair in the existence of polyvinyl chloride (PVC) and o-nitrophenyl octyl ether (o-NPOE). Clear peaks at 270, and 303 nm with band gaps of 4.59 eV and 4.09 eV were measured using UV-vis spectroscopy of Al2O3 and CeO2, respectively. The crystallite sizes of the formed nanoparticles were XRD-determined to be 30.13 ± 8, 17.72 ± 3, and 35.8 ± 0.5 nm for Al2O3, CeO2, and Al2O3/CeO2 NCS, respectively. The developed sensor showed excellent response for the measurement and assay of DCF, with a linearity between 1.0 × 10-9 and 1.0 × 10-2 mol L-1. EmV = (57.76) log [DCF] +622.69 was derived. On the other hand, the typical type DCF-PM presented a potentiometric response range of 1.0 × 10-5-1.0 × 10-2 mol L-1 and a regression equation of EmV = (56.97) log [DCF]+367.16. The functionalized sensor that was proposed was successful in determining DCF in its commercial tablets with percent recovery 99.95 ± 0.3. Method validation has been used to improve the suitability of the suggested potentiometric technique, by studying various parameters with respect to the international council harmonization requirements for analytical methodologies.

A Dual-Mode Spectrophotometric and Fluorescent Probe Based on Lignin-Derived Carbon Dots for the Detection of Atorvastatin Calcium in a Bulk Powder and a Commercial Product.

Recently, dual-mode techniques have garnered considerable attention and have been shown to be effective approaches for biomedical analysis and environmental monitoring. A novel and simple dual-mode spectrophotometric and fluorometric probe based on lignin-derived carbon dots (LCDs) was developed to detect atorvastatin calcium (ATS) in a bulk powder and its commercial product. The synthesized LCDs exhibit exceptional fluorescence characteristics and are highly soluble in water while maintaining reasonable stability. The average particle size of the LCDs was 3.42 ± 1.03 nm. The characterization of the produced LCDs indicated a structure resembling graphene oxide with the presence of several functional groups. The developed LCDs show a good fluorescence quantum yield of 32.2%. The fluorescence of the LCDs is quenched by ATS at an emission wavelength of 315 nm after excitation at 275 nm through dynamic and static quenching mechanisms. The optimal reaction conditions for the dual-mode reaction were a pH of 9 and 0.05 mL of the LCDs, which were measured after 3 min at 30 °C by spectrophotometry, followed by 7 min at 20 °C by fluorometric methods. According to the spectrophotometric results, the response of ATS was linear in the range of 4.0-100.0 µg/mL, while according to the fluorometric results, the dynamic range was 3.0-50.0 µg/mL. The limits of detection (LODs) and the limits of quantification (LOQs) were 0.97 µg/mL and 2.95 µg/mL for the fluorometric method, respectively. The nanoprobe effectively analyzed ATS in medication samples and yielded good results.

Plant extract mediated synthesis of ZnO and CeO2 nanoparticles for spectrofluorometric assay of omeprazole and domperidone in pharmaceuticals.

The current research proposed a highly sensitive and selective spectrofluorometric approach for the assay of gastrointestinal medications omeprazole (OMZ) and domperidone (DOM). Green synthesis of metal oxide nanoparticles such as zinc oxide (ZnONPs) and cerium oxide (CeO2NPs) using Pimpinella anisum and Syzygium aromaticum extract was used as fluorescence emission catalysts for the determination of OMZ and DOM. Due to their unique optical properties, nanoparticles (NPs) form the basis for spectrofluorimetric quantification of the selected drugs. The detection studies were performed under λex/λem 350/450 nm and 284/392 nm for OMZ and DOM in the presence of ZnONPs and CeO2NPs, respectively. Under ideal conditions, fluorescence intensities (FI) were linearly with correlation coefficient (r = 0.999) over concentration ranges of 0.1-100 and 0.01-200 µg mL-1 for OMZ, 0.01-100 and 0.01-300 n g mL-1 for DOM in the presence of ZnONPs and CeO2NPs, respectively. Method validation was carried out to guarantee the accuracy, suitability, and precision of the proposed fluorescence (FL) systems for the determination of OMZ and DOM. Analytical method guidelines and requirements were followed. The designed procedure was used effectively to identify the determined drugs in both their pure and commercial versions.

Comparative Study for Spectrofluorimetric Determination of Ambroxol Hydrochloride Using Aluminum Metal Transfer Chelation Complex and Biogenic Synthesis of Aluminum Oxide Nanoparticles Using Lavandula spica Flowers Extract.

The existing study pronounces two newly developed spectrofluorimetric probes for the assay of ambroxol hydrochloride in its authentic and commercial formulations using an aluminum chelating complex and a biogenically mediated and synthesized aluminum oxide nanoparticles (Al2O3NPs) from Lavandula spica flower extract. The first probe is based on the formation of an aluminum charge transfer complex. However, the second probe is based on the effect of the unique optical characteristics of Al2O3NPs in the enhancement of fluorescence detection. The biogenically synthesized Al2O3NPs were confirmed using various spectroscopic and microscopic investigations. The fluorescence detections in the two probes were measured at a λex of 260 and 244 and a λem of 460 and 369 nm for the two suggested probes, respectively. The findings showed that the fluorescence intensity (FI) covered linear concentration ranges of 0.1-200 ng mL-1 and 1.0-100 ng mL-1 with a regression of ˃0.999 for AMH-Al2O3NPs-SDS and AMH-Al(NO3)3-SDS, respectively. The lower detection and quantification limits were evaluated and found to be 0.04 and 0.1 ng mL-1 and 0.7 and 0.1 ng/mL-1 for the abovementioned fluorescence probes, respectively. The two suggested probes were successfully applied for the assay of ambroxol hydrochloride (AMH) with excellent percentage recoveries of 99.65% and 99.85%, respectively. Excipients such as glycerol and benzoic acid used as additives in pharmaceutical preparations, several common cations, and amino acids, as well as sugars, were all found to have no interference with the approach.

Ultrasensitive Functionalized Polymeric-Nanometal Oxide Sensors for Potentiometric Determination of Ranitidine Hydrochloride.

Two metal oxide nanoparticles, magnesium oxide nanoparticles (MgONPs) and aluminum oxide nanoparticles (Al2O3NPs), were synthesized from green sources, Salvia officials and Cuminum cyminum seed extract, respectively. These nanoparticles were used for construction of potentiometric enhancement sensors employed for the estimation of ranitidine hydrochloride (RNT) in authentic powder and commercial products. The electroactive substance ranitidine-phosphotungstate (RNT-PT) was formed by combining RNT with phosphotungstic acid (PTA) in the presence of plasticizing material o-nitrophenyloctyl ether (o-NPOE). The outcomes showed that the enhanced MgO and Al2O3 nanosensors behaved linearly across the concentration ranges 1.0 × 10-9-1.0 × 10-2 and 1.0 × 10-10-1.0 × 10-2 mol L-1, respectively. However, the conventional sensor (RNT-PT) displayed a linearity over 1.0 × 10-6-1.0 × 10-2 mol L-1. Least square equations were calculated as EmV = (54.1 ± 0.5) log (RNT) + 762.33, EmV = (58.6 ± 0.2) log (RNT) + 696.48, and EmV = (52.2 ± 0.7) log (RNT) + 756.76 for enriched nanometal oxides modified and conventional sensors, respectively. The correlation coefficients of regression equations were 0.9997, 0.9995, and 0.9992 for the above suggested sensors, respectively. The recorded results showed excellent sensitivity and selectivity of the modified nanometal oxide sensors for the quantification of the analyzed drug in its authentic samples and commercial products.

Prospects for using a new sequential chemiluminescence strategy for monitoring the caffeine content in soft and energy drinks via the catalytic activities of different nano-metal oxides.

This article suggests a new sequential injection analysis chemiluminescence (SIA-CL) strategy for monitoring the caffeine (CAF) content in soft and energy drinks using the catalytic activities of different nano-metal oxides. The present study describes three different SIA-CL systems (luminol-ferricyanide (III) coupled with Fe2 O3 or ZnO nanoparticles (NPs), and luminol-H2 O2 coupled with CuONPs. All experimental conditions were optimized and the linear concentration ranges of pure CAF were evaluated using the calibration graphs. The selectivity of the developed SIA-CL systems was studied under the influence of various interfering species that may be present in soft or energy drinks such as sodium ions, sucrose, glucose, sodium benzoate, sodium citrate, riboflavin, niacin, citric, phosphoric and ascorbic acids. International Council for Harmonization (ICH) guidelines were obeyed for the validation of the suggested CL methods. The developed SIA-CL systems displayed linear relationships over the concentration ranges 1.0-350, 5.0-400 and 10.0-400 µg ml-1 with Fe2 O3 NPs, ZnO NPs and CuO NPs, respectively. The recorded lower limits of detection and quantification were 0.7, 2.7 and 7.8 µg ml-1 , and 1.0, 5.0 and 10.0 µg ml-1 for the previously mentioned SIA-CL systems. The results revealed high selectivity for CAF determination and were in good agreement with those obtained by other reported methods.