- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Sulfur doped graphene quantum dots as a potential sensitive fluorescent probe for the detection of quercetin
摘要： In this work, a novel, selective and sensitive fluorescent probe (sulfur doped graphene quantum dots, SGQDs) was designed for real-time detection of quercetin in red wine samples. SGQDs were synthesized by pyrolyzing citric acid (CA) and 3-Mercaptopropionic acid (MPA) and characterized through advanced techniques. It was observed that fluorescence intensity of SGQDs could be substantially quenched by the addition of quercetin through inner filter effect (IFE) mechanism. Additionally, a visual color change (colorless to light yellow) was also noticed after addition of quercetin into a solution of SGQDs. The change in SGQDs fluorescence intensity with varying quercetin content revealed good linearity in the 0-50.0 μM range with regression coefficient of 0.9943 and a lowest detection limit of 0.006 μg/mL. To authenticate the real-time application of SGQDs as a potential fluorescent probe, red wine samples having different quercetin concentrations were used for quantitative analysis, after the optimization of several analytical parameters.
关键词： Sulfur doped graphene quantum dots,inner filter effect,pharmaceutical assay,fluorescent probe,quenching,quercetin
更新于2025-09-23 15:19:57
-
MICRODETERMINATION OF CARVEDILOL AND ARIPIPRAZOLE USING HAEMATOXYLIN DYE IN PURE FORM AND PHARMACEUTICAL FORMULATIONS USING SPECTROPHOTOMETRY
摘要： The current study reports about simple, rapid, sensitive and economic spectrophotometric method for determination of the antihypertensive, Carvedilol (CRV) and the antipsychotic, Aripiprazole (ARP) in pure form and pharmaceutical formulations. The suggested method is based on reaction of the studied drugs with haematoxylin reagent in the presence of boric acid to give a reddish violet chromogen at λmax= 560 nm. The percentage recoveries for the suggested method were 99.78±1.10 and 99.97±1.2 within the concentration ranges of 3-16 μg/mL and 8-32 μg/mL for Carvedilol and Aripiprazole respectively. Results show a minimum detection limit (LOD) of 0.63 and 1.79 μg/mL and a quantification limit (LOQ) of 1.91 and 5.42 μg/mL for Carvedilol and Aripiprazole respectively. The method showed excellent precision, with intra and inter-assay precisions of less than 2.0% at all concentrations. The suggested method was applied successfully for determination of the cited drugs in pure form and pharmaceutical formulations without interference of common pharmaceutical excipients with the method procedure. The suggested method was proved to be valid by analyzing both pure and pharmaceutical formulations, comparing the results obtained with those of the reported methods and demonstrating good accuracy and precision results.
关键词： Pharmaceutical formulations,Spectrophotometry,Aripiprazole,Carvedilol,haematoxylin dye
更新于2025-09-23 15:19:57
-
Sol-gel Syntheses of Photocatalysts for the Removal of Pharmaceutical Products in Water
摘要： A screening study on seven photocatalysts was performed to identify the best candidate for pharmaceutical products degradation in water. Photocatalysts were deposited as thin films through a sol-gel process and subsequent dip-coating on glass slides. The efficiency of each photocatalyst was assessed through the degradation of methylene blue first, and then, through the degradation of 15 different pharmaceutical products. Two main types of synthesis methods were considered: aqueous syntheses, where the reaction takes place in water, and organic syntheses, where reactions take place in an organic solvent and only a stoichiometric amount of water is added to the reaction medium. Photocatalysts synthesized via aqueous sol-gel routes showed relatively lower degradation efficiencies; however, the organic route required a calcination step at high temperature to form the photoactive crystalline phase, while the aqueous route did not. The best performances for the degradation of pharmaceuticals arose when Evonik P25 and silver nanoparticles were added to TiO2, which was synthesized using an organic solvent. In the case of methylene blue degradation, TiO2 modified with Evonik P25 and TiO2 doped with MnO2 nanoparticles were the two best candidates.
关键词： sol-gel process,thin films,pharmaceutical products,TiO2,photocatalysis
更新于2025-09-19 17:15:36
-
SILICA a?? CARBON QUANTUM DOTS DECORATED TITANIUM DIOXIDE AS SUNLIGHT-DRIVEN PHOTOCATALYST TO DIMINISH ACETAMINOPHEN FROM AQUATIC ENVIRONMENT
摘要： The presence of pharmaceutical compound (i.e., acetaminophen) in aquatic environment has been declared as environmental issue since researchers found that it has potential risk to human health. Photocatalytic process as a promising method for waste degradation commonly employs titanium dioxide, TiO2. However, TiO2 has narrow light absorption and rapid charge recombination resulting in ineffective photocatalytic activity. In this study, silica – carbon quantum dots (Si-CQDs) from rice husk are decorated into TiO2 matrix through facile mixing approach to minimize the limitations of TiO2. Preliminary studies regarding TiO2 transformation and Si-CQDs incorporation in various amount were systematically investigated. It is observed that 1 wt% is the optimum amount of Si-CQDs in composite in order to maximize the photocatalytic ability of TiO2. Under sunlight irradiation, 1 wt% Si-CQDs/TiO2 composite is able to completely degrade 5 mg/L of acetaminophen within 240 min (33.3% faster than pure TiO2). The excellent performance of the composite is attributed to synergistic effect of Si-CQDs addition on TiO2 surface, which acted as photo sensitizer and electron trapper. Si-CQDs extend light absorption of TiO2 by reducing band gap energy from 3.20 to 3.12 eV, as confirmed by UV-Vis Diffuse Reflectance Spectroscopy (DRS) spectra. Photoluminescence (PL) spectra and N2 sorption isotherm reveal that Si-CQDs addition prolongs the lifetime of charge separation and improves surface area (17% larger than TiO2), respectively. The composite of Si-CQDs/TiO2 also demonstrates good stability which is beneficial for pharmaceutical waste removal in the future.
关键词： sunlight,photocatalyst,Titanium dioxide,acetaminophen,carbon quantum dots,pharmaceutical
更新于2025-09-19 17:13:59
-
Carbon quantum dots as a fluorophore for “inner filter effect” detection of metronidazole in pharmaceutical preparations
摘要： With houttuynia cordata as carbon source, photoluminescent carbon quantum dots (CDs) were obtained via a one-step hydrothermal procedure. The absorption band of metronidazole (MNZ, maximum absorption wavelength at 319 nm) can well overlap with the excitation bands of CDs (maximum excitation wavelength at 320 nm). A fluorescent approach has been developed for detection of MNZ based on the inner filter effect (IFE), in which as-prepared CDs act as an IFE fluorophore and the MNZ as an IFE absorber. We have investigated the mechanism of quenching the fluorescence of CDs and found that the IFE leads to an exponential decay in fluorescence intensity of CDs with increasing concentration of MNZ, but showed a good linear relationship (R2 ? 0.9930) between ln(F0/F) with the concentration of MNZ in the range of 3.3 (cid:2) 10(cid:3)6 to 2.4 (cid:2) 10(cid:3)4 mol L(cid:3)1. Due to the absence of surface modification of the CDs or establishing any covalent linking between the absorber (MNZ) and the fluorophore (CDs), the developed method is simple, rapid, low-cost and less time-consuming. Meanwhile, it possesses a higher sensitivity, wider linear range, and satisfactory selectivity and has potential application for detection of MNZ in pharmaceutical preparations.
关键词： metronidazole,carbon quantum dots,inner filter effect,pharmaceutical preparations,fluorescence detection
更新于2025-09-16 10:30:52
-
Synthesis of N-doped TiO <sub/>2</sub> /SiO <sub/>2</sub> /Fe <sub/>3</sub> O <sub/>4</sub> magnetic nanocomposites as a novel purple LED illumination-driven photocatalyst for photocatalytic and photoelectrocatalytic degradation of naproxen: optimization and different scavenger agents study
摘要： N-doped TiO2/SiO2/Fe3O4 as a new magnetic photocatalyst that is active in visible light has been prepared by simple sol–gel method. The prepared samples were characterized by XRD, FESEM, EDX, TEM, BET, BJH, VSM, XPS, FT-IR, and DRS–UV/Vis analysis. The photocatalytic effect of synthesized samples on naproxen degradation was studied. The operational parameters were optimized through central composite design to achieve maximum efficiency. The optimum values for maximum efficiency were obtained at pH of 4.29, catalyst mass of 0.06 g, naproxen concentration of 9.33 mg L(cid:1)1, and irradiation time of 217.06 min. At these optimum conditions, the maximum photocatalytic degradation percentages of naproxen were found to be 96.32% at desirability function value of 1.0. Coupling the electrical current with the photocatalytic process proved that the electrical current was considerably efficient in decreasing the degradation time of removing the naproxen from aqueous solutions. The photocatalytic activity of the nanoparticles was also studied under sunlight. Considering the results provided by UV–Vis spectrophotometry and total organic carbon, it was found that the prepared samples are extraordinarily efficient to degrade naproxen under both purple LED and solar lights. Furthermore, the effect of different scavenger agents on naproxen degradation has been studied.
关键词： pharmaceutical compound,experimental design,Photodegradation,core–shell nanocomposite,titanium dioxide
更新于2025-09-16 10:30:52
-
Deep UV laser-induced fluorescence for pharmaceutical cleaning validation
摘要： Cleaning verification and validation is a requirement in the pharmaceutical industry. Due to the limited number of mobile devices that do effective and accurate onsite cleaning verification, it is mostly done via lab-based quality control techniques. These techniques, such as High-Performance Liquid Chromatography (HPLC) or Total Organic Carbon, often lead to extending the validation of cleaning by days. The void of more sensitive, accurate, and portable instruments to verify cleaning onsite has to be filled. The article discusses the use of Deep Ultra Violet (DUV) laser-induced fluorescence for detecting carryover of Active Pharmaceutical Ingredients (APIs) and detergents onsite. A modified spectrometer was used as an offsite bench type prototype for analyzing trace samples of API and cleaning detergents with various substrates. Even if the API to be detected has a low fluorescence efficiency, the specificity of the technique allows API traces having concentrations as low as ≈0.20 μg/cm2 to be identified. The work also shows the possibility of using a probe for validating cleaning of hard to reach areas using DUV laser-induced fluorescence. DUV laser-induced fluorescence of trace API over any polymer/glass substrate has better Signal to Background Ratio (SBR) compared to FTIR absorption techniques. Processing times of DUV laser-induced fluorescence trace detection are shown to be much less than swab based methods.
关键词： Active Pharmaceutical Ingredients (APIs),pharmaceutical cleaning validation,Deep Ultra Violet (DUV),signal to background ratio (SBR),laser-induced fluorescence
更新于2025-09-12 10:27:22
-
Quantum dots based “on-off” fluorescence probe for the selective detection of Cu2+ ion: Application to real samples analysis
摘要： Turn ‘On-Off’ quantum dot-based fluorescent probe has been developed for the selective detection of Cu2+. This strategy achieved by consecutively fluorescence enhancement and quenching of mercapto propionic acid (MPA) capped cadmium sulphide quantum dots (MPA-CdS QDs) by the addition of D-penicillamine (D-PA) and Cu2+ respectively. After successive addition of Cu2+ in CdS QDs- (D-PA) system, the fluorescence intensity of quantum dots decrease due to the removal of D-PA molecules from the surface of QDs as well as selective ion exchange process takes place between Cu2+ and Cd2+ at the surface of QDs. At optimal conditions, probe offers a good response in the linear range between 4 ng/mL and 40 ng/mL with LOD 2.71 ng/mL. This reported strategy is a very simple and selective towards Cu2+. Hence, a new method for the potential detection of Cu2+ in real pharmaceutical samples can be developed by using QDs-based fluorescence probe.
关键词： Fluorescence probe,quantum dots,pharmaceutical sample,quenching
更新于2025-09-12 10:27:22
-
Direct Z-scheme 2D/2D MnIn2S4/g-C3N4 architectures with highly efficient photocatalytic activities towards treatment of pharmaceutical wastewater and hydrogen evolution
摘要： Semiconductor photocatalysis has been regarded as an environmentally friendly technology in wastewater treatment and energy production. Here, a series of direct Z-scheme MnIn2S4/g-C3N4 (MnISCN) photocatalysts without electron mediators were fabricated by a simple hydrothermal route on the basis of in-situ loading of MnIn2S4 (MnIS) nanoflakes on the surface of g-C3N4 (CN) nanosheets. Photocatalytic performances evaluated under visible light irradiation revealed these Z-scheme heterostructured photocatalysts exhibited higher photocatalytic activities than single-component samples. The effect of weight ratio between MnIn2S4 nanoflakes and mesoporous CN nanosheets on photocatalytic activity towards treatment of pharmaceutical wastewater was optimized to achieve highly efficient photocatalytic activities for both degradation of pharmaceutical wastewater and hydrogen generation compared with alone MnIS nanoflakes and isolated mesoporous CN nanosheets. The significant enhancement in photocatalytic activity could be primarily ascribed to the construction of Z-scheme MnISCN architectures, which effectively accelerated the transfer and separation of photogenerated charge carriers via tight interface contacts built among these two components. The recycling experiments for pharmaceutical wastewater treatment revealed the excellent stability of MnISCN nanocomposites. The advantages of highly efficient photocatalytic activity and excellent stability endowed a promising potential for MnISCN nanocomposites to apply in photocatalytic fields.
关键词： pharmaceutical wastewater,g-C3N4,hydrogen evolution,Z-scheme,MnIn2S4
更新于2025-09-10 09:29:36
-
Visible photodegradation of ibuprofen and 2,4-D in simulated waste water using sustainable metal free-hybrids based on carbon nitride and biochar
摘要： Rational designing of metal-free carbon nitride based photocatalysts can lead to an excellent optical response and a higher photocatalytic activity driven by visible and solar light. This combines green photocatalytic technology with greener materials prepared by facile approaches for environmental remediation. Herein we report utilization of star photocatalyst g-C3N4 (CN) to form highly efficient hetero-assemblies along with acidified g-C3N4 (ACN), polyaniline (PANI), reduced graphene oxide (RGO) and biochar. By use of these organic semiconductors we synthesize g-C3N4/ACN/RGO@Biochar (GARB), g-C3N4/PANI/RGO@Biochar (GPRB) and ACN/PANI/RGO@Biochar (APRB) nano-assemblies with different optical response and band edge positions for a better charge flow and reduced recombination of carriers. These synthesized catalysts were used for visible light powered degradation of 2,4-Dichlorophenoxy acetic acid (2,4-D) and ibuprofen (IBN). APRB performs the best and degrades 99.7% and 98.4% of 2,4-D and IBN (20 mg L?1) under Xe lamp exposure in 50 min and retention of high activity in natural sunlight. Optical analysis, photoelectrochemical response and radical quenching studies show both hydroxyl and superoxide radical anions as major reactive species and a Z-scheme photocatalytic mechanism. RGO acts as an electron mediator and protects higher positioned bands of PANI and ACN in APRB for a remarkable photocatalytic activity for a metal free material. The degradation pathway was analyzed by LC-MS analysis and 42% and 40% total organic carbon was removed in 2 h for 2,4-D and IBN degradation respectively. The toxicity of degraded products was analyzed by analyzing viability of human peripheral blood cells with retaining of 99.1% cells.
关键词： Water treatment,Carbon nitride,Nano-assemblies,Environmental detoxification,Biochar: pharmaceutical effluents,Photocatalysis
更新于2025-09-10 09:29:36