Cholesterol vs Ergosterol: Influence on the Dynamic and Structural Properties of the Cobalt-Based Metallosomal Bilayer Membrane.

Sterol derivatives are a crucial part of liposomes, as their concentration and nature can induce significant alternations in their characteristic features. For natural liposomal-based (phospholipid-based) studies, the bulk literature is already present depicting the role of the concentration or nature of different sterol derivatives in modulation of membrane properties. However, the studies aiming at evaluating the effect of sterol derivatives on synthetic liposomal assemblies are limited to cholesterol (Chl), and a comparative effect with other sterol derivatives, such as ergosterol (Erg), has never been studied. To fill this research gap, through this work, we intend to provide insights into the concentration-dependent effect of two sterol derivatives (Chl and Erg) on a synthetic liposomal assembly (i.e., metallosomes) prepared via thin film hydration route using a double-tailed metallosurfactant fabricated by modifying cetylpyridinium chloride with cobalt (Co) (i.e., Co:CPC II). The morphological evaluations with cryogenic-transmission electron microscopy (cryo-TEM), atomic force microscopy (AFM), and field emission-scanning electron microscopy (FE-SEM) indicated that metallosomes retained their spherical morphology irrespective of the nature and concentration of sterol derivatives. However, the size, ζ-potential, and lamellar width values were significantly modified with the incorporation of sterol derivatives in a concentration-dependent manner. In-depth studies affirmed that the extent of modulation of the bilayer in terms of hydrophobicity, fluidity, and rigidity was more severe with Chl than Erg. Such differences in the membrane properties lead to their contrasting behavior in the delivery of the broad-spectrum active compound "curcumin". From entrapment to in vitro behavior, the metallosomes demonstrated dissimilar behavior as even though Erg-modified metallosomes (at higher concentrations of Erg) exhibited low entrapment efficiency, they still could easily release >80% of the entrapped drug. In vitro studies conducted with Staphylococcus aureus bacterial cultures further revealed an interesting pattern of activity as the incorporation of Chl reduced the toxicity of the self-assembly, whereas their Erg-modified counterparts yielded slightly augmented toxicity toward these bacterial cells. Furthermore, Chl- and Erg-modified assemblies also exhibited contrasting behavior in their interaction studies with bacterial DNA.

Label free dual-mode sensing platform for trace level monitoring of ciprofloxacin using bio-derived carbon dots and evaluation of its antioxidant and antimicrobial potential.

Being a persuasive antibiotic, ciprofloxacin is widely administered to patients and its excessive discharge has generated a keen interest among researchers for its detection in water resources. Therefore, the current work utilizes the virtues of carbon dots synthesized from the leaves of Ocimum sanctum as an economical and convenient bimodal stratagem for the detection of ciprofloxacin via an electrochemical and fluorometric approach. The insight into photostability, size, morphology, and optical studies of the carbon dots was tested to enhance their scope in sensing. The excellent photoluminescence-based excitation-dependent behavior with a quantum yield of 46.7% and non-requirement of any kind of labeled surface variations for amending their fluorescence and electrochemical properties have further supported the utilization of as-prepared carbon dots in trace-level monitoring of ciprofloxacin. The fluorescence emission intensity and peak current were enhanced by many folds via the application of Ocimum sanctum-derived carbon dots. The synergetic effect of carbon dots has possessed a linear relationship between the peak current/emission intensity within the range of 0 to 250 µM of ciprofloxacin and the lowest detection limit value was found to be 0.293 and 0.0822 µM with fluorometric and electrochemical methods, respectively. The sensor demonstrated excellent applicability for the estimation of ciprofloxacin and acts as a high-performance dual sensor for further applications.

Sustainable agronomic response of carbon quantum dots on Allium sativum: Translocation, physiological responses and alternations in chromosomal aberrations.

The revolutionary growth in the usage of carbon quantum dots (CQDs) in different areas have ultimately directed their discharge in the environment and further augmented the exposure of agricultural crops to these released particles. Therefore, the aim of current study is to evaluate the uptake, translocation and phytotoxicity of blue emissive CQDs on Allium sativum plant. The genotoxicity and cytotoxicity assessment of CQDs towards Allium sativum roots was estimated as function of three different concentrations. Considering the role of CQDs in promoting seed germination at 50 ppm concentration, a greenhouse experiment was performed to evaluate their effect on plant growth. Systematic investigations have shown the translocation of CQDs and their physiological response in terms of increased shoot length wherein P-CQDs exhibited more accumulation into Allium sativum parts. Our investigations unfold the opportunity to utilize Aegle marmelos fruit derived CQDs as a growth regulator in variety of other food plants.

Bio-Derived Fluorescent Carbon Dots: Synthesis, Properties and Applications.

The transformation of biowaste into products with added value offers a lucrative role in nation-building. The current work describes the synthesis of highly water-soluble, luminous carbon quantum dots (CQDs) in the size range of 5-10 nm from discarded rice straw. The small spherical CQDs that were formed had outstanding optical and luminescent qualities as well as good photostabilities. By performing quantitative multi-assay tests that included antioxidant activities, in vitro stability and colloidal assay investigations as a function of different CQD concentrations, the biocompatibility of CQDs was evaluated. To clearly visualize the type of surface defects and emissive states in produced CQDs, excitation-dependent fluorescence emission experiments have also been carried out. The "waste-to-wealth" strategy that has been devised is a successful step toward the quick and accurate detection of Cu2+ ion in aqueous conditions. The fluorescence-quenching behavior has specified the concentration dependency of the developed sensor in the range of 50 µM to 10 nM, with detection limit value of 0.31 nM. The main advantage of the current research is that it offers a more environmentally friendly, economically viable and scaled-up synthesis of toxicologically screened CQDs for the quick fluorescence detection of Cu2+ ions and opens up new possibilities in wastewater management.

Voltammetric detection of vitamin D employing Au-MoS2 hybrid as immunosensing platform.

A voltammetric immunosensor based on molybdenum sulphide (MoS2) and gold nanoparticles (Au NPs) for the determination of 25-hydroxy vitamin D3 (25(OH)D3) is reported. Anti-vit D (Ab-25(OH)D3) was immobilized onto the cysteamine-modified MoS2 and Au NPs which were deposited onto a fluoride tin oxide (FTO) electrode (Ab/Cys/Au/MoS2/FTO). The MoS2 sheets were prepared by hydrothermal method followed by an in situ growth of Au film onto the MoS2/FTO surface. Self-assembled monolayer (SAM) of cysteamine was synthesized onto the Au/MoS2/FTO which acts as a linker to covalently bind Ab-25(OH)D3. The Ab-25(OH)D3-immobilized Cys/Au/MoS2/FTO was used to detect 25(OH)D3 using differential pulse voltammetry. The electrochemical system provided an anodic peak current at a potential of +0.21 V vs. Ag/AgCl (satd. KCl) of ferricyanide/ferrocyanide redox couple. The detection principle relies on the inhibition of electron transfer at the electrode surface owing to the hindrance caused by the formation of immune complex between Ab-25(OH)D3 and 25(OH)D3. The immunosensor shows linear response from 1 pg mL-1 to 100 ng mL-1 25(OH)D3 and a sensitivity of 189 µA [log (pg mL-1)]-1 cm-2 along with a low limit of detection (LOD) of 0.38 pg mL-1. The immunosensor is highly selective towards 25(OH)D3 and presented a long shelf life of 28 days. Also, the immunosensor exhibits satisfactory performance towards spiked human serum samples with recovery between 95.1 and 102% (RSD 1.15-3.22%).

Investigating the efficiency of α-Bismuth zinc oxide heterostructure composite/UV-LED in methylene blue dye removal and evaluation of its antimicrobial activity.

Heterostructured α-Bismuth zinc oxide (α-Bi2O3-ZnO) photocatalyst was fabricated by a facile and cost-effective, ultrasound assisted chemical precipitation method followed by hydrothermal growth technique. As synthesized α-Bi2O3-ZnO photocatalyst showed enhanced photocatalytic performance for the MB dye degradation in contrast to pure ZnO and α-Bi2O3. Light emitting diodes (UV-LED) were used in the experimental setup, which has several advantages over conventional lamps like wavelength selectivity, high efficacy, less power consumption, long lifespan, no disposal problem, no warming-up time, compactness, easy and economic installation. XRD study confirmed the presence of both the lattice phases i.e. monoclinic and hexagonal wurtzite phase corresponding to α-Bi2O3 and ZnO in the α-Bi2O3-ZnO composite photocatalyst. FESEM images showed that α-Bi2O3-ZnO photocatalyst is composed of dumbbell like structures of ZnO with breadth ranging 4-5 µm and length ranging from 10 to 11 µm respectively. It was observed that α-Bi2O3 nanoparticles were attached on the ZnO surface and were in contact with each other. Low recombination rate of photo-induced electron-hole pairs, due to the migration of electrons and holes between the photocatalyst could be responsible for the 100% photocatalytic efficiency of α-Bi2O3-ZnO composite. In addition, photocatalyst was also observed to show the excellent antimicrobial activity with 1.5 cm zone of inhibition for 1 mg L-1 dose, against the human pathogenic bacteria (S. aureus).

Synthesis, thermal and surface activity of cationic single chain metal hybrid surfactants and their interaction with microbes and proteins.

A series of water-soluble metal functionalized surfactants have been prepared using commercially available surfactant cetyl pyridinium chloride and transition metal salts. These complexes were characterized in the solid state by elemental analysis, FTIR, 1H NMR and thermogravimetric analysis. The interfacial surface activity and aggregation behaviour of the metallosurfactants were analysed through conductivity, surface tension and small angle neutron scattering measurements. Our results show that the presence of metal ions as co-ions along with counter ions favours micellization at a low critical micellization concentration (CMC). Small angle neutron scattering revealed that the metallomicelles are of a prolate ellipsoidal shape and exhibit strong counterion binding. This article further describes the interaction of the metallosurfactants with transport protein Bovine Serum Albumin (BSA) using different spectroscopic techniques. A spectroscopic study was used to study the binding, interaction and quenching mechanism of BSA with the metallosurfactants. Gel electrophoresis (SDS-PAGE) and circular dichroism (CD) investigated the structural and conformational changes produced in BSA due to the metallosurfactants. The results indicate that there is an alteration in the secondary structure of BSA due to the electrostatic interaction between positive head groups and metal co-ions of the metallosurfactants and negatively charged amino acids of BSA. As the concentration increases, the α-helicity of BSA decreases and all the three studied metallosurfactants gave comparable results. Finally, the in vitro cytotoxicity and antimicrobial activity of the metallosurfactants were evaluated against erythrocytes and microorganisms, which showed prominent effects related to the presence of a metal ion in metallomicelles of the hybrid surfactants.

Green synthesis of CuO nanomaterials and their proficient use for organic waste removal and antimicrobial application.

Copper oxide (CuO) nanomaterials (NMs) of different size and morphology were synthesized by Chemical precipitation, Microwave irradiation and Hydrothermal method and characterized by TEM, BET, FTIR, XRD and EDX analysis. As synthesized CuO NMs were utilized for elimination of harmful dyes viz. Direct Red 81 (DR-81) and Coomassie Brilliant blue R-250 (BBR-250) and pathogenic bacteria (Staphylococcus aureus). Owing to their morphology, smaller size and relatively high surface area (40.320 m2 g-1), CuO NMs prepared by chemical precipitation method were observed to show better adsorption capacity for both the dyes (68.70 (DR-81) and 73.04 (BBR-250) mg g-1). The influence of different experimental conditions was studied by the methodical assessments of various parameters such as pH, adsorbent dose, concentration and contact time. Moreover, different adsorption isotherms and pseudo-second order kinetic model were applied to understand the adsorption mechanism. Langmuir model was found to be best fit thus confirming the monolayer adsorption process. To ensure the practical utility of CuO NMs for organic waste removal, the adsorption studies were performed in the presence of different inorganic ions and real water samples. In addition, recovery of the dye and NMs were also carried out effectively by simple method, thus avoiding the secondary pollution. CuO NMs were observed to exhibit significant antibacterial activity against the human pathogenic bacteria. These studies demonstrated that synthesized CuO NMs showed good adsorption efficiency for the removal of harmful dyes and antimicrobial activity against the pathogenic bacteria, which vary as a function of size and surface area.

Cationic double chained metallosurfactants: synthesis, aggregation, cytotoxicity, antimicrobial activity and their impact on the structure of bovine serum albumin.

Bovine serum albumin (BSA) is one of the most copious and significant blood proteins with dynamic structure. The understanding of the structural functionality of BSA and its interaction with metal ions is desired for various biological functions. Herein, three different metallosurfactants containing different transition metals and the same hydrophobic tail were engaged to investigate the structural transition of BSA. The metallosurfactants have been prepared by a combination of metal ions (M = Fe, Co and Ni) with cetylpyridinium chloride surfactant via the ligand insertion method and were characterized by elemental, FTIR, 1H-NMR, and thermogravimetric analysis (TGA). The obtained results reveal that insertion of a metal ion perturbs the aggregation behavior of the surfactant. Incorporation of a metal-ion has been found to decrease the CMC value of the surfactant, which has been supported by conductivity, surface tension and small angle X-ray scattering (SAXS). These metallosurfactants were employed to study the interaction and binding mechanism of BSA under physiological conditions. SDS-PAGE analysis points out a weak effect of metallosurfactants on the primary structure of BSA, whereas CD spectra implied a significant change in secondary structure with the decreased α-helical content of BSA. Fluorescence spectroscopy indicates the effect of metallosurfactants on the tertiary structure of BSA, whereas absorption spectra demonstrated static quenching with a blue shift in the presence of metallosurfactants. Moreover, unfolding of BSA in the presence of metallosurfactants has also been confirmed by SAXS studies. The overall results indicate that insertion of the metal ion into the framework of the surfactant structure enhances its protein binding/folding/unfolding abilities, which would be helpful in clinical as well as in life sciences.

Fabrication of metalosomes (metal containing cationic liposomes) using single chain surfactants as a precursor via formation of inorganic organic hybrids.

Among the self-assembled forms of surfactants, vesicles/liposomes are a highly promising and interesting feature of surfactants, which are usually formed from water insoluble surfactants. Herein, we demonstrate the formation of liposomes from single-chain cationic surfactants with the help of metals as a part of the counter ion, and these metal embedded liposomes are termed as metalosomes. It is a noteworthy advancement in the area of self-assembled molecular structures since we report the preparation of metal embedded liposomes (metalosomes) from a water soluble single chain cationic surfactant, which is otherwise a property or an arrangement made by double tailed surfactants, or more precisely lipids that are poorly water soluble. We can use this method for various cationic surfactants and metal combinations and the studies are still in process. However, this preliminary report on manganese-based surfactants depicts the successful formation of cationic metalosomes (with/without cholesterol), and the formation, structure and size has been verified using TEM, FE-SEM, DLS XRD and SAXS. The comparison of metalosomes with reverse vesicles in different solvents further gave an insight of microstructure and solvent environment effects on the self-assembly of metallosurfactants. In addition, we have also evaluated the encapsulation ability of metalosomes for fluorescein dye. High encapsulation efficiency of Mn-somes makes them promising candidates for several applications, particularly because of its water solubility.

Multifaceted approach for the fabrication of metallomicelles and metallic nanoparticles using solvophobic bisdodecylaminepalladium (II) chloride as precursor.

A one-pot synthesis of solvophobic bisdodecylaminepalladium(II) chloride (complex 1) was performed. Complex 1 was characterized using X-ray crystallography and other techniques, namely, mass spectrometry, Fourier transform infrared, NMR, elemental analysis, etc. A multifaceted approach was taken to explore the potential applications of complex 1. The micellization ability of complex 1 was estimated using conductivity method in n-alcohols. The metallomicelles are formed in alcohols, and the process is thermodynamically spontaneous in nature. Using complex 1 as precursor, palladium (Pd) nanoparticles were fabricated using two-phase redox method, where reduction is being performed in core of metallomicelles formed by complex 1 in dichloromethane (DCM). The micellization in DCM is confirmed by small-angle X-ray scattering (SAXS). The SAXS measurements reveal that the micellar of core 4-5 nm is being formed, which further controls the size of nanoparticle. This approach was advantageous in terms of size control, methodology, and yield. Pd nanoparticles were characterized using transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and UV-visible spectroscopy and were also screened for bovine serum albumin interactions. Complex 1 and Pd nanoparticles were found to possess antimicrobial property with broad spectrum and are active against bacteria and fungi. The cytotoxicity analyses were performed over healthy cells (Vero cell lines extracted from kidney of green monkey), and the results reveal IC50 value of 10 µg/mL for complex 1.

Gamma-Fe2O3 nanospindles for environmental remediation: a study on the adsorption and desorption characteristics of acridine orange and direct red dyes.

In this paper, the adsorption and desorption characteristics of two harmful dyes, i.e., acridine orange (AO; cationic dye) and direct red 81 (DR; anionic dye) from aqueous solutions onto gamma-Fe2O3 nanospindles have been investigated. The nanospindles were synthesized by facile chemical precipitation method and characterized in detail in terms of their morphological, compositional and optical properties. Batch mode experiments were conducted to examine the adsorption process by investigating several factors such as effect of pH, amount of adsorbent dose, and effect of dye concentrations. The experimental results indicated that the maximum adsorption capacity occurred at pH = 6.0 for AO and at pH = 4.0 for DR, respectively with 0.03 gm of adsorbent. Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models have been used to evaluate the ongoing adsorption. Kinetic parameters for the adsorption have also been applied. Moreover, the gamma-Fe2O3 nanospindles and the adsorbed dyes were desorbed with good performance and could be reused to absorb the dyes again.

Removal of water contaminants by iron oxide nanomaterials.

In recent years, there has been increasing concern about the usage of a broad range of organic substances, heavy metals and aromatic compounds in the aquatic environment due to their wide distribution and potential adverse health effects. The presence of toxic contaminants in water effluent, even at very low concentrations, is extremely harmful and undesirable. Various treatment processes have been investigated to reduce these toxic pollutants from wastewater. Because of the chemical stability of the contaminants, these technologies have proved to be ineffective for handling waste effluents. Nanotechnology offers the possibility of efficient removal of pollutants as nanoparticles have a smaller size and higher adsorptive surface area. From the past few years, nanoscale iron oxides such as magnetite, maghemite, and hematite have been used for the separation and removal of organic and inorganic contaminants. In this review we summarize the use of iron oxide nanomaterials performed over the last few years for the removal of dyes, heavy metals and aromatic compounds.

Lateral flow assemblies and allied application of carbon quantum dots derived from cigarette tobacco in biosensing, anticounterfeiting and fluorescent films: Theoretical and experimental overview.

The bio-sensing activity of fluorescence based nanoprobes is one of the most significant aspects to scrutinize the analytical pursuance in modern security and lateral flow assays. Herein, potent transmogrification of waste cigarette tobacco into fluorescent carbon quantum dots (CQDs) has been achieved by calcination approach. The waste transformation to CQDs holds diverse benefits, comprising high quantum yield, low toxicity and scale up synthesis. The developed CQDs were able to identify tetracycline with phenomenal selectivity and sensitivity through fluorescence based method. The sensing mechanism was fully explored using Density Functional Theory (DFT) and Molecular docking studies. Governing features comprising tetracycline concentration, interfering studies, and real water analysis on the identification of tetracycline were also investigated. Along with, the prepared CQDs act as colorimetric probe, facilitating the detection of tetracycline with the naked eye. The lateral flow device was constructed for the on-site detection of tetracycline in real water samples. To the best of our knowledge, the present work represents a novel approach to designing CQDs and demonstrates their significant potential for application in anticounterfeiting measures and lateral flow devices. This work holds significant prospective as the prepared CQDs was fully utilized to its maximum usage in developing films and fluorescent anti-counterfeiting applications. Concisely, current work opens up distinctive opportunities for rapid on-site, real-time and visualized surveillance of tetracycline using CQDs prepared with a quite simple green approach.

Recent advancements and prospects in carbon-based nanomaterials derived from biomass for environmental remediation applications.

The conversion of waste biomass into a value-added carbonaceous nanomaterial highlights the appealing power of biomass valorization. The advantages of using sustainable and cheap biomass precursors exhibit the tremendous opportunity for boosting energy production and their application in environmental remediation processes. This review emphasis the development and production of carbon-based nanomaterials derived from biomass, which possess favourable characteristics such as biocompatibility and photoluminescence. The advantages and limitations of various nanomaterials synthesised from different precursors were also discussed with insights into their physicochemical properties. The surface morphology of the porous nanomaterials is also explored along with their characteristic properties like regenerative nature, non-toxicity, ecofriendly nature, unique surface area, etc. The incorporation of various functional groups confers superiority of these materials, resulting in unique and advanced functional properties. Further, the use of these biomass derived nanomaterials was also explored in different applications like adsorption, photocatalysis and sensing of hazardous pollutants, etc. The challenges and outcomes obtained from different carbon-based nanomaterials are briefly outlined and discussed in this review.

Metallosurfactant aggregates: Structures, properties, and potentials for multifarious applications.

Metallosurfactants offer important scientific and technological advances due to their novel interfacial properties. As a special class of structures formed by the integration of metal ions into amphiphilic surfactant molecules, these metal-based amphiphilic molecules possess both organometallic and surface chemistries. This review critically examines the structural transitions of metallosurfactants from micelle to vesicle upon metal coordination. The properties of a metallosurfactant can be changed by tuning the coordination between the metal ions and surfactants. The self-assembled behavior of surfactants can be controlled by selecting transition-metal ions that enhance their catalytic efficiency in environmental applications by applying a hydrogen evolution reaction or oxygen evolution reaction. We present the different scattering techniques available to examine the properties of metallosurfactants (e.g., size, shape, structure, and aggregation behavior). The utility of metallosurfactants in catalysis, the synthesis of nanoparticles, and biomedical applications (involving diagnostics and therapeutics) is also explored.

Adsorption studies of cationic, anionic and azo-dyes via monodispersed Fe3O4 nanoparticles.

The present paper reports the applicability of magnetite (Fe3O4) nanoparticles as an adsorbent for the removal of three dyes viz. Acridine orange (cationic dye), Comassie Brilliant Blue R-250 (anionic dye) and Congo red (azo dye) from their aqueous solution. The Fe3O4 nanoparticles were synthesized via simple chemical precipitation method using CTAB, as surfactant. The as-prepared nanoparticles were characterized in terms of their morphological, structural and optical properties by using transmission electron microscopy X-ray diffraction and UV-visible spectroscopic measurements. The dye removal efficiency of Fe3O4 NPs have been determined by investigating several factors such as effect of pH, amount of adsorbent dose and effect of contact time on different dye concentrations. Langmuir and Freundlich adsorption isotherms have also been studied to explain the interaction of dyes. The experimental data indicate that the adsorption rate follows pseudo- second-order kinetics for the removal of all the three dyes. Moreover, the nanoparticles and the adsorbed dyes were desorbed. The identities of recovered nanoparticles as well as the three dyes have been found, as same and were reused.

MC-Au/MSS-Z8 porous network assisted advanced electrochemical immunosensing of 25-hydroxyvitamin D3.

On-site monitoring of vitamin D levels is subject matter of immediate attention owing to the serious aftermath of its long standing deficiency. Therefore, a novel and efficient voltammetric immunosensing of 25-hydroxyvitamin D3 (25(OH)VD3) has been experimented based on an advanced sensing platform composed of meso-microporous silica-zeolitic imidazolate framework-8 (MSS-Z8) with highly enhanced surface area (SBET, MSS-Z8 (643.4 m2g-1) > SBET, MSS (49.95 m2g-1)), embedded with gold particles (mass loading of 82 µg), particularly of microcubic morphology (MC-Au). Further, the MC-Au/MSS-Z8/FTO platform was fashioned with antibody specific to 25(OH)VD3 via interaction between Au and abundant -SH groups present on the antibody surface. After optimization of operational parameters, the Ab/MC-Au/MSS-Z8/FTO immunosensor was employed for the determination of 25(OH)VD3 within 0.01-106 pg mL-1 concentration range through differential pulse voltammetry technique in [Fe(CN)6]3-/4-. Thus, 0.01 pg mL-1 concentration of 25(OH)VD3 was the experimental limit of detection of the immunosensor. Further, upon examination of various analytical parameters, it turns out that the immunosensor exhibited low theoretical LOD (0.23 pg mL-1) and LOQ (0.76 pg mL-1), wide linear range (0.01-106 pg mL-1), ultra-sensitivity (143.9 µA [log (pg mL-1)]-1 cm-2), adequate reproducibility (RSD ≤1.23%) and acceptable shelf life. Most importantly, the immunosensor presented proficient performance with spiked human serum samples (Recovery = 97.20-100.7%, RSD value < 5.6%), evincing the adequacy of present biosensing approach.

Biogenic synthesis of highly fluorescent carbon dots using Azadirachta indica leaves: An eco-friendly approach with enhanced photocatalytic degradation efficiency towards Malachite green.

A simpler and efficient method has been developed for the green synthesis of highly fluorescent carbon dots (CDs) from Azadirachta Indica leaves. The surface morphology of developed CDs has shown the existence of spherical particles in the size range of 3-8 nm with superior biocompatibility and high quantum yield value i.e. 42.3%. The particles exhibited a highly fluorescent and crystalline nature along with a bandgap value of 4.02 eV. The prepared CDs served as a factorial design for the sensing and degradation of Malachite green among other dyes. The main perspective of the current finding is that the designed catalyst exhibits excellent sensing results towards Malachite green with a limit of detection i.e. 0.144 µM in the concentration range of 0-50 µM. Moreover, the UV triggered results of photocatalysis illustrated a good dye removal efficacy by developed CDs with an average of 90.73, 98.25, 52 and 6.13% degradation in Methylene blue (MB), Malachite green (MG), Rhodamine 6G (Rh 6G) and Methyl orange (MO) upon 70 min of irradiation with mercury lamp. Additionally, the proton NMR, FTIR and FESEM results of the recycled samples also confirm the complete degradation of MG dye with the application of N-CDs.

3-Methoxyazetidin-2-one Functionalized CuO-CB Microfibrils: A Drug Formulation with Controlled Release and Enhanced Synergistic Antibacterial Activities.

trans-1-(4'-Methoxyphenyl)-3-methoxy-4-phenyl 3-methoxyazetidin-2-one (or 3-methoxyazetidin-2-one) is one of the important ß-lactam derivatives with an ample range of bacterial activities yet few restrictions. To enhance the competency of the chosen 3-methoxyazetidin-2-one, microfibrils composed of copper oxide (CuO) and filter scraps of cigarette butts (CB) were chosen in the current work for developing a potential release formulation. The preparation of CuO-CB microfibrils required a simple reflux technique and a subsequent calcination treatment. The loading of 3-methoxyazetidin-2-one was processed via controlled magnetic stirring followed by centrifugation with microfibrils of CuO-CB. To confirm the loading efficiency, the 3-methoxyazetidin-2-one@CuO-CB complex was analyzed by scanning electron microscopy, transmission electron microscopy, and infrared spectroscopy. Compared to the CuO nanoparticles, the release profile of CuO-CB microfibrils indicates only 32% of the drug release in the first 1 h at pH 7.4. As a model organism, E. coli has been utilized for in vitro drug release dynamic studies. Based on the observed drug release data, it was found that the prepared formulation evades premature drug release and triggers the on-demand release of drug inside bacterial cells. The controlled drug release by 3-methoxyazetidin-2-one@CuO-CB microfibrils over a period of 12 h further ascertained the excellent bactericide delivery mechanism to combat deadly bacterial resistance. Indeed, this study provides a strategy to combat antimicrobial resistance and eradicate bacterial disease via nanotherapeutics.