Cd Nanoparticles Research Articles

Green Synthesis of Bimetallic Cu−Cd Nanoparticles and its Catalytic Activity in Pyrido [2,3‐d;6,5‐d] Dipyrimidine Derivatives

AbstractGreen synthesis nanoparticles have gained interest in recent years due to their environmental friendliness and sustainability. The current study focuses on the green synthesis of BMNP using spearmint leaves as a reducing and stabilizing agent. Because of their excellent catalytic characteristics, the synthesized bimetallic nanoparticles function as an effective catalyst in pyrido[2,3‐d:6,5‐d] pyrimidine derivatives. The synthesized nanoparticles are characterized using a variety of techniques, including FT‐IR analysis, SEM & EDX, XRD, and TEM. The FT‐IR study shows a reduction in functional groups in the leaf extract, confirming the metal nanoparticles’ stretching. SEM and EDX studies confirm the shape and elemental composition of bimetallic nanoparticles. XRD investigation showed that the synthesized NPs are crystalline, and the Scherrer equation was used to calculate the average crystallite size. The calculated size was 49 nm. TEM analysis confirms the core‐shell nature of BMNPs. The synthesized nanoparticles acted as a superior catalyst in pyrido[2,3‐d:6,5‐d] dipyrimidines derivatives. in the synthetic procedure, BMNPs enhanced the catalytic activity and reduced the reaction time with more yield, Compared to the previous study. and the synthesized compound [1–5] has been confirmed by FT‐IR, 1H‐NMR, and 13C‐NMR analysis. and it has given better results in in‐vivo anti‐diabetic activity by Streptozotocin nicotinamide. This induced model adult male albino Wistar derivatives show significant fasting blood glucose levels when compared to metformin hydrochloride. and its evaluated molecular docking study, exhibit excellent CDDOCKER energy.

Upcycling spent Ni–Cd battery for selective synthesis of nanoparticles to harness into electro-conductive thin films: An eco-friendly approach for e-waste management

Inspired by Sustainable Development Goal-12 (responsible consumption and production) to reduce e-waste, an environment friendly extraction of Cd, Ni and Co from Ni–Cd spent batteries have been reported here using ammonium chloride as a chlorinating agent for the first time. Multiple parameters i.e. dose of chlorinating agent, roasting time, and temperature has been optimized that resulted in extraction of 99.93 % Cd, 90.1 % Ni and 84.81 % Co. Metal enriched leachate was then subjected to unique precipitation steps that resulted in synthesis of Cd nanoparticles, Co3O4·NiO composite nanoparticles, and NiO nanoparticles, characterized through XRD and FESEM-EDX. Synthesized nanoparticles were further employed in the fabrication of electro-conductive nano thin films via Layer by Layer (LbL) technique. Film buildup of six novel architectures was monitored using an Ellipsometer. Homogenous film growth was tailored by optimizing ratio, concentration and dipping time of nanoparticles and polymer solutions. Conductivity studies revealed that imbedding synthesized nanoparticles impart significant conductive behavior in thin films with maximum conductivity of 1.8 × 10−4 S/cm, in addition to exhibiting appreciable resistance against 0.1 M HCl, 0.1 M NaOH and acetone. Contact angle and AFM images revealed that the films were slightly wettable and homogenous respectively. Conclusively not only Cd, Ni and Co were successfully recycled from Ni–Cd spent batteries employing greener technique but were also harnessed into robust nano-thin films with focus towards electro-conductivity based applications.

Synthesis of Cd-Cu nanoparticles supported on HOPG for use as electrocatalytic material for nitrate reduction

Bimetallic nanoparticles application has attracted great attention in the field of electrocatalysis because they can enhance the catalytic properties toward certain reactions of technological interest, such as nitrate reduction. For this purpose, Cd-Cu bimetallic nanoparticles were prepared on highly oriented pyrolytic graphite substrates by sequential electrodeposition of both metals. The process was studied by conventional electrochemical techniques, and the generated deposits were characterized by scanning electron microscopy − energy dispersive X-ray spectroscopy analysis. Initially, Cu nanoparticles were prepared by a simple potentiostatic pulse applied to the carbonaceous substrate. Scanning electron microscopy images showed high density of mainly hemispherical-shaped Cu crystals distributed preferably on step edges and surface defects of the highly oriented pyrolytic graphite electrode. Subsequently, Cd particles were prepared in the same way by immersing the Cu nanoparticles / highly oriented pyrolytic graphite modified substrate in an electrolyte solution containing Cd2+ ions, exploiting the phenomenon of underpotential deposition. It was evidenced that the existing crystals grew in size, most of them showing the typical shapes of those for Cd nanoparticles. The application of the Cd-Cu nanoparticles / highly oriented pyrolytic graphite electrode as a feasible electrocatalyst material for nitrate reduction was investigated by cyclic voltammetry for different nitrate concentrations, also considering the possibility of using this procedure as a method for the anion detection.

Synthesis and Characterisation of Ag-Co-Venlafaxine-Cyclodextrin Nanorods

Ag and Ag/Co nanoparticles containing venlafaxine/cyclodextrin (VF/CD) inclusion complexes were synthesized and analyzed by UV-Visible, fluorescence, computational technique, DSC, FTIR, XRD, FE-SEM, and TEM. Single emission was observed in α-CD and β-CD. A blue-shifted absorption and fluorescence maximum was seen in Ag/VF/CD and Ag/Co/VF/CD nanoparticles than VF/CD inclusion complex. TEM image exposed the existence of nanorods in Ag/VF/β-CD and Ag/Co/VF/β-CD. Pure VF drug shows more antibacterial activity than Ag/VF/β-CD and Ag/Co/VF/β-CD nanomaterials. Nano particle size is also measured by X-RD and TEM.

Multi-metal contaminant mobilizations by natural colloids and nanoparticles in paddy soils during reduction and reoxidation

Naturally-occurring colloids and nanoparticles are crucial in transporting heavy metal contaminants in soil-water systems. However, information on particle-bound metals’ size distribution and elemental composition in paddy soils under redox-fluctuation is scarce. Here, we investigated the mobilization of Cu, Cd, and Pb-containing nanoparticles and colloids in four contaminated soils with distinctive geochemical properties during reduction and subsequent re-oxidation. Using AF4-UV-ICP-MS and STEM-EDS, we observed that particle-bound metals were primarily associated with two sizes ranges: 0.3−40 kDa (F1) and 130 kDa−450 nm (F2), which mainly consisted of organic matter (OM), iron hydroxide and clay minerals. Cu and Pb were more likely bound to colloid than Cd. Colloidal Cu, Pb and Cd accounted for averages of 83.2%, 72.4% and 19.8% of their total concentration in solution (<0.45 µm) during soil reduction, and decreased during soil re-oxidation. This proportion was also positively correlated with aqueous pH and DOC but negatively correlated with Eh. Further quantitative analysis demonstrated that Cu/Cd positively correlated with OM at nanometric scale (F1). This study provides quantitative insights into the size, composition and abundance of polymetallic pollutant-carrying particles in paddy soils during redox fluctuation, and highlights the importance of nanometric interactions between OM and toxic cationic metals for their release.

Green Synthesis of Polylactic acid/Fe3O4@β-Cyclodextrin Nanofibrous Nanocomposite Loaded with Ferulago Angulata Extract as a Novel Nano-biosorbent: Evaluation of Diazinon Removal and Antibacterial Activity.

Organophosphate pesticides are one of the most extensively applied insecticides in agriculture. These insecticides persist in the environs and thereby cause severe pollution problems. Iron oxide polymer nanocomposites are wastewater remediation agents synthesized by various methods. When compared to chemical processes, green synthesis using plant extract is thought to be more cost- and environmentally-friendly. This study aimed to evaluate the green synthesis of Fe3O4@β-Cyclodextrin (Fe3O4@β-CD) nanoparticles using Ferulago angulata (F. angulata) methanol extract. These nanoparticles are loaded on polylactic acid (PLA) nanofibrous nanocomposite along with Ferulago angulata extract (2, 4, and, 6wt %) to produce PLA/Fe3O4@β-CD/F. angulata extract nanofibrous nanocomposite as a new nano biosorbent. Furthermore, the antibacterial properties of this compound and its activity in diazinon removal have been evaluated. Fe3O4@β-CD nanoparticles synthesis was performed via co-precipitation method using FeCl3.6H2O and FeCl2.4H2O and β-cyclodextrin, and Ferulago angulata extract. Then polylactic acid/ Fe3O4@β-CD / F. angulate.extract nanofibrous nanocomposite was prepared by the electrospinning method. Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD), vibrating sample magnetometer (VSM), and Fourier transform infrared spectroscopy (FTIR) were used to analyze the structure of the nanocomposite. The antibacterial activity of this nanocomposite against several fish and human bacterial pathogens, as well as its effectiveness in diazinon elimination, have been evaluated in the sections that follow. The nanocomposite structure demonstrated that Fe3O4 nanoparticles were produced and put into the polylactic acid matrix with an average particle size of 40 nm. Furthermore, the results showed that this nanocomposite exhibited removal efficiency of diazinon over 80% after 120 minutes under pH=7 and 2.5 gr.L-1 nanocomposite concentration. Also, this structure showed above 70% antibacterial ability against Bacillus cereus, Staphylococcus epidermidis and 60% antibacterial ability against Streptococcus iniae and Yersinia ruckeri. Fe3O4 nanocomposite synthesis may be accomplished in a delicate and efficient manner by using Ferulago angulata to produce Fe3O4@-CD nanoparticles. The stability of the nanoparticles was enhanced by combining Ferulago angulata extract with polylactic acid nanofibers to create an antibacterial homocomposition nanocomposite. This device may be used to remove and disinfect diazinon from aqueous media in an environmentally friendly manner.

A green synthetic approach for the morphological control of ZnO-Ag using β-cyclodextrin and honey for photocatalytic degradation of bromophenol blue

Green synthetic approaches aid control of physicochemical properties of nanoparticles and decrease the environmental footprint of the nanoparticles. Herein, novel synthesis of ZnO nanoparticles (NPs) using natural surfactants and sequential investigation of their optical, physicochemical and photocatalytic properties are conducted. This work utilizes β-cyclodextrin (βCD) and honey as surfactants during the production process. It is demonstrated that these natural surfactants have the ability to control size, shape, crystalline phase growth and dispersion of NPs (denoted as ZnO-C and ZnO-H). Subsequent coupling of ZnO NPs with Ag to form the binary nanostructures (ZnO-xAg, ZnO-C-xAg and ZnO-H-xAg) further assists controlling their physicochemical properties. With a variation of Ag NPs loading, the 3 wt% Ag loaded nanophotocatalysts were more efficient and their associated properties were revealed by various characterization techniques. Nanoparticles of different shapes were fabricated with a surface area of up to 10 m2.g−1 and crystalline sizes of 9.38 nm. Photoluminescent spectroscopy indicated that Ag nanoparticles enhanced the life span of electron-hole pairs. Thus, photodegradation of bromophenol blue (BPB) indicated enhanced NPs photoactivity upon modification with CD, honey, and Ag NPs. BPB photodegradation was > 99.84% using ZnO-H-3Ag with reaction rates of k0app=518.8×10−2min−1 and up to 75% total organic carbon was removed by ZnO-H-3Ag at a rate of 8.19×10−3min−1.

A comparative study of smart nanoformulations of diethyldithiocarbamate with Cu4O3 nanoparticles or zinc oxide nanoparticles for efficient eradication of metastatic breast cancer

Metastatic tumor is initiated by metastatic seeds (cancer stem cells “CSCs”) in a controlled redox microenvironment. Hence, an effective therapy that disrupts redox balance with eliminating CSCs is critical. Diethyldithiocarbamate (DE) is potent inhibitor of radical detoxifying enzyme (aldehyde dehydrogenase “ALDH”1A) causing effective eradication of CSCs. This DE effect was augmented and more selective by its nanoformulating with green synthesized copper oxide (Cu4O3) nanoparticles (NPs) and zinc oxide NPs, forming novel nanocomplexes of CD NPs and ZD NPs, respectively. These nanocomplexes exhibited the highest apoptotic, anti-migration, and ALDH1A inhibition potentials in M.D. Anderson-metastatic breast (MDA-MB) 231 cells. Importantly, these nanocomplexes revealed more selective oxidant activity than fluorouracil by elevating reactive oxygen species with depleting glutathione in only tumor tissues (mammary and liver) using mammary tumor liver metastasis animal model. Due to higher tumoral uptake and stronger oxidant activity of CD NPs than ZD NPs, CD NPs had more potential to induce apoptosis, suppress hypoxia-inducing factor gene, and eliminate CD44+CSCs with downregulating their stemness, chemoresistance, and metastatic genes and diminishing hepatic tumor marker (α-fetoprotein). These potentials interpreted the highest tumor size reduction with complete eradicating tumor metastasis to liver in CD NPs. Consequently, CD nanocomplex revealed the highest therapeutic potential representing a safe and promising nanomedicine against the metastatic stage of breast cancer.

On the formulation of disulfide herbicides based on aminophenoxazinones: polymeric nanoparticle formulation and cyclodextrin complexation to combat crop yield losses.

The resistance of weeds to herbicides is a significant issue in ensuring future food supply. Specific examples are Plantago lanceolata, Portulaca oleracea and Lolium rigidum, which mainly infect rice, wheat, barley and pastures, and cause high yield losses every year. In this regard, natural products and their mimics have provided new hope as a result of their different modes-of-action, activity at low concentrations and reduced pollution effects relative to conventional herbicides. However, the poor water solubility and physicochemical properties of these compounds limit their broad application. These problems can be addressed by formulation techniques, and encapsulation appears to be of great interest. Disulfide herbicides inspired by aminophenoxazinones have been formulated with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), γ-CD and polymeric nanoparticles (NPs). In silico studies were employed to identify which complexes would be generated and complex formation was confirmed by nuclear magnetic resonance spectroscopy. Solubility diagrams were generated to assess any improvement in water solubility, which was enhanced 2-13-fold. Scanning electron microscopy and energy-dispersive X-ray spectra confirmed the success of the formulation process for the nanoparticles. Formulated compounds were evaluated in an in vitro wheat coleoptile bioassay, with almost 100% elongation inhibition achieved using only water for the bioassay. Specific in vitro testing on weed phytotoxicity showed that the application of core/shell NPs is highly effective in the fight against P.lanceolata seed germination. The formulation of disulfide herbicides with CD complexes and NPs led to an enhancement in water solubility and bioactivity. These systems can be applied in pre-emergent mode against P.lanceolata, using only water to prepare the sample, and they showed better activity than the positive controls. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Cytotoxicity and anti-biofilm activities of biogenic cadmium nanoparticles and cadmium nitrate: a preliminary study.

Wild-type microorganisms have become tolerant to higher antibiotic and antimicrobial agent concentrations due to the global increase in antibiotic consumption. Green-synthesized nanoparticles (NPs) have been proposed as potential antimicrobial agents to overcome the problem. This research prepared cadmium nanoparticles (Cd NPs) using Artemisia persica extract. To clarify the biological behavior of Cd NPs and Cd (NO3)2, cytotoxicity, antibacterial, anti-biofilm, and biocompatible experiments were performed. Since Cd toxicity is associated with liver, kidney damage, and other deficits, HepG2 and HUVEC cell lines were employed as the in vitro cytotoxicity models. Cd NPs had a lower cytotoxic effect than Cd (NO3)2 against both HepG2 and HUVEC cells. The Cd NPs exhibited no hemolysis activity. The antibacterial and anti-biofilm studies were conducted using gram-positive Staphylococcus aureus and gram-negative Proteus mirabilis and Pseudomonas aeruginosa with the ability to form severe adherent biofilms. The antibacterial activity of Cd NPs against clinically isolated S. aureus, P. mirabilis, and P. aeruginosa was above 2560µg mL- 1. The Cd NPs (640µg mL- 1) decreased the biofilm formation of S. aureus, P. mirabilis, and P. aeruginosa by 24.6%, 31.6%, and 26.4%, respectively.Moreover, adding Cd NPs (100µg/disc) to antibiotic discs increased the antibacterial activity of vancomycin, gentamicin, tetracycline, streptomycin, meropenem, and kanamycin against Methicillin-resistant S. aureus, significantly. Due to the emergence of resistant microorganisms, Cd NPs can be used as an exciting material to counterattack global health problems. Further research is needed to clarify the molecular mechanisms underlying Cd NPs' pharmacological and toxicological effects.

Photoinduced self-stability mechanism of CdS photocatalyst: The dependence of photocorrosion and H2-evolution performance

• The lattice Cd 2+ reduction during CdS photocorrosion was carefully investigated. • The isolated Cd nanoparticles were produced on CdS surface in Na 2 S-Na 2 SO 3 system. • A metallic Cd layer is uniformly coated on CdS surface in the lactic acid system. • A photoinduced self-stability mechanism of CdS photocatalyst has been proposed. CdS photocorrosion is one of the most important factors that greatly affect the photocatalytic H 2 -production rate and long-time stability. However, the reported works about CdS photocorrosion are mainly focused on the surface oxidation by photogenerated holes, while the possible reduction of lattice Cd 2+ by photogenerated electrons is usually ignored. In this work, the lattice Cd 2+ reduction by photogenerated electrons during CdS photocorrosion were carefully investigated to reveal its potential effect on the microstructure change and photocatalytic H 2 -production performance of CdS photocatalyst based on the two typical Na 2 S-Na 2 SO 3 and lactic acid H 2 -evolution systems. It was found that many isolated metallic Cd nanoparticles (5–50 nm) were produced on the CdS surface in the Na 2 S-Na 2 SO 3 system, causing its serious destroy of CdS surface and a gradually decreased photocatalytic activity, while only a metallic Cd layer (2-3 nm) is homogeneously coated on the CdS surface in the lactic acid system, leading to an increased H 2 -evolution rate. In fact, once a certain amount of metallic Cd was produced on the CdS surface, the resulting CdS-Cd composites can present a stable photocatalytic H 2 -production activity and excellent stability for the final CdS-Cd photocatalysts. Hence, a photoinduced self-stability mechanism of CdS photocatalyst has been proposed, namely, the spontaneously produced metallic Cd contributes to the transformation of unstable CdS into stable CdS-Cd structure, with the simultaneous realization of final stable H 2 -evolution performance.

Optical Detection of Acetone Using “Turn-Off” Fluorescent Rice Straw Based Cellulose Carbon Dots Imprinted onto Paper Dipstick for Diabetes Monitoring

Persistent bad breath has been reported as a sign of serious diabetes health conditions. If an individual’s breath has a strong odor of acetone, it may indicate high levels of ketones in the blood owing to diabetic ketoacidosis. Thus, acetone gas in the breath of patients with diabetes can be detected using the current easy-to-use fluorescent test dipstick. In another vein, rice straw waste is the most well-known solid pollutant worldwide. Thus, finding a simple technique to change rice straw into a valuable material is highly important. A straightforward and environmentally friendly approach for reprocessing rice straw as a starting material for the creation of fluorescent nitrogen-doped carbon dots (NCDs) has been established. The preparation process of NCDs was carried out via one-pot hydrothermal carbonization using NH4OH as a passivation substance. A testing strip was developed on the basis of cellulose CD nanoparticles (NPs) immobilized onto cellulose paper assay. The NCDs demonstrated a quantum yield of 23.76%. A fluorescence wavelength was detected at 443 nm upon applying an excitation wavelength of 354 nm. NCDs demonstrated remarkable selectivity for acetone gas as their fluorescence was definitely exposed to quenching by acetone as a consequence of the inner filter effect. A linear correlation was observed across the concentration range of 0.5–150 mM. To detect and measure acetone gas, the present cellulose paper strip has a “switch off” fluorescent signal. A readout limit was accomplished for an aqueous solution of acetone as low as 0.5 mM under ambient conditions. The chromogenic fluorescence of the cellulose assay responsiveness depends on the fluorescence quenching characteristic of the cellulose carbon dots in acetone. A thin fluorescent cellulose carbon dot layer was deposited onto the surface of cellulose strips by a simple impregnation process. CDs were made using NP morphology and analyzed using infrared spectroscopy and transmission electron microscopy. The carbon dot distribution on the paper strip was evaluated by scanning electron microscope and energy-dispersive X-ray analysis. The absorption and fluorescence spectral analyses were investigated. The paper sheets’ mechanical qualities were also examined.

Synthesis of Au-Cd ablated on porous silicon for photodetector applications

ABSTRACT Colloidal nanoparticles (NPs) of Au:Cd were prepared via laser ablation in liquid with several energies of laser and then were deposited on porous-Si (PS). X-ray diffraction, scanning electron microscopy, UV - visible spectrophotometry and electrical attributes were used to characterise the obtained particles. From photodetector measurements, the spectral responsivity curves include three area; the first area represent absorption of UV light by Au:Cd NPs, the second area is due to the visible light absorption with the layer of PS and the third region to the absorption edge of the substrate Si. The higher responsivity of Au:Cd NPs/PS photodetector was found to be 2.66A/W for the sample prepared at a laser energy of 800 mJ/pulse that has the largest energy gap, and according to the quantum confinement effects, the size of NPs is smaller Thus, the surface area is greater and is also considered a major feature in improving the photodetector.

Interaction of hyperaccumulating plants with Zn and Cd nanoparticles

Metal hyperaccumulating plant species are an interesting example of natural selection and environmental adaptation but they may also be useful to developing new technologies of environmental monitoring and remediation. Noccaea caerulescens and Arabidopsis halleri are both Brassicaceae and are known metal hyperaccumulators. This study evaluated tolerance, uptake and translocation of zinc sulfide quantum dots by N. cearulescens and cadmium sulfide quantum dots by A. halleri in direct comparison with the non-hyperaccumulator, genetically similar T. perfoliatum and A. thaliana. Growth media were supplied with two different concentrations of metal in either salt (ZnSO4 and CdSO4) or nanoscale form (ZnS QDs and CdS QDs). After 30 days of exposure, the concentration of metals in the soil, roots and leaves was determined. Uptake and localization of the metal in both nanoscale and non-nanoscale form inside plant tissues was investigated by Environmental Scanning Electron Microscopy (ESEM) equipped with an X-ray probe. Specifically, the hyperaccumulators in comparison with the non-hyperaccumulators accumulate ionic and nanoscale Zn and Cd in the aerial parts with a BCF ratio of 45.9 for Zn ion, 49.6 for nanoscale Zn, 2.64 for Cd ion and 2.54 for nanoscale Cd. Results obtained with a differential extraction analytical procedure also showed that a significant fraction of nanoscale metals remained inside the plants in a form compatible with the retention of at least a partial initial structure. The molecular consequences of the hyperaccumulation of nanoscale materials are discussed considering data obtained with hyperaccumulation of ionic metal. This is the first report of conventional hyperaccumulating plants demonstrating an ability to hyperaccumulate also engineered nanomaterials (ENMs) and suggests a potential novel strategy for not only understanding plant-nanomaterial interactions but also for potential biomonitoring in the environment to avoid their entering into the food chains.

POS-220 DEVELOPING RENAL CLEARABLE NANOPARTICLES FOR THE TREATMENT OF RENAL CELL CARCINOMA

Nanoparticles (NPs) have been anticipated to revolutionise health care based on their potential to improve drug delivery. However, the design of effective cancer nano-therapeutics remains a challenge, and only a few nanoparticles have entered clinical trial. The majority of current NPs when administered intravenously are known to accumulate in lungs, liver, spleen & kidney and cause organ damage. Metastatic Renal Cell Carcinoma (RCC) is incurable, with median survival time of only 18 months, and currently there are no effective NP-based therapeutics. To effectively treat RCC and eliminate the side effects caused by NP organ accumulation, we have developed renal clearable NPs based on carbon material (Carbon Dots, CD). The aim of this project is to develop novel NPs with size less than 5.5nm as a vehicle to carry chemotherapeutic drugs such as Doxorubicin (DOX). The nanoparticles should possess renal clearable properties to target RCC and avoid non-specific distribution of drug causing adverse side effects. The study includes NP design and characterisation, drug conjugation, uptake of NPs and outcome measures. The properties of NPs were characterised, and the drug loading capacity was determined. The effect of drug and its conjugates were assessed initially in vitro. The pH difference between cancer cells and normal cells has been used as the triggering mechanism for DOX release. The cell viability of CD NPs, free DOX and CD-DOX conjugate were investigated in Renca and Hela cells by the MTT assay after 24 and 48 hr treatment. The development of an in vivo tumour model is in progress. We have successfully developed a novel type CD Nanoparticles by one-step synthesis. The Transmission Electron microscopy images revealed the CDs are spherical with an average diameter of 4nm. These CDs were shown to have low cytotoxicity with cell viability of higher than 90% at concentrations up to 200ug/ml; possess high quantum yield (58%) with bright blue fluoresce observed under UV light; very high drug loading capacity (93%). The maximum emission wavelength is at 440 nm upon excitation at 340 nm. The excitation-dependent photoluminescence properties allowed visual monitoring of the cells in blue, green and red fluorescence channels. The effective delivery and uptake of CDs into the cell’s cytoplasm was observed within 2 hrs by confocal microscopy. The cell viability assay demonstrated that CD-DOX significantly reduced the viability of the Renca cells by 2-fold compared to free DOX (24% vs 50% respectively, P value=0.0167). In Hela cells, the cell viability was furthermore reduced by 10-fold with CD-DOX compared to free DOX (5.5% vs 57.5% respectively, P value=0.0001). We have developed Carbon Dot nanoparticles with size <5.5nm with low cytotoxicity. The carbon dots have high drug loading capacity and show better inhibition of growth in cancer cell lines compared to unbound chemotherapeutics, suggesting that these nanoparticles have therapeutic potential in renal cell carcinoma.

Structure, Optical, Dielectric, and Magnetic Properties of Zn0.99M0.01O (M = Ni, Fe, and Cd) nanoparticles

Zn0.99M0.01O (M = Ni, Fe, and Cd) nanoparticles have been prepared by a co-precipitation technique. X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), and Fourier transformation infrared spectroscopy (FTIR) have been used to characterize the prepared samples. XRD patterns showed that ZnO has a hexagonal wurtzite structure with an average particle size of 22.9 nm, which decreased by the addition of metals ions to ZnO. EDS exhibited the existence of Cd, Ni, and Fe which asserts the substitution of metal ions inside ZnO matrix. The UV-Visible spectra revealed an absorbance increase and a band gap decrease by metals ions addition. Dielectric permittivity (e`), electric modulus (M``), and ac conductivity (σac) were also studied as a function of temperature and frequency. e` was found to increases with metal ions addition, and a relaxation peak appears at low frequency in M`` spectra. σac(T) was thermally activated and the activation energy Ea decreased with metal ions addition. A ferromagnetic behavior with a hysteresis loops was observed for Zn0.99M0.01O at room temperature. These results suggest that Zn0.99M0.01O is suitable for optoelectronic device applications or as a novel way for the incorporation of magnetic ions in the semiconductor materials.

Synthesis of carbon dots@Fe3O4 and their photocatalytic degradation properties to hexaconazole

The CD@Fe3O4 photocatalysts were synthesized via hydrothermal synthesis method. The CD@Fe3O4 particles were synthesized using Fe3O4 as the core and using citric acid and ethylenediamine as a raw material, which were heated to 200 °C for 4 h. The synthesized fluorescent CD@Fe3O4 was characterized by HR-TEM, IR and fluorescence spectrophotometer. The HR-TEM results showed CD and Fe3O4 nanoparticles were uniform, mono-dispersed sphere or hemisphere particles with an average size of approximately 3 nm, and particle size of CD@Fe3O4 were mainly in range of 20–30 nm. XRD results showed the nanoparticles mainly belonged to Fe3O4 and CD@Fe3O4, which made recycling our photocatalysts possible due to the magnetic performance. On daylight lamp, the half-life of hexaconazole in CD@Fe3O4 photocatalysts was about 4 days, and it is lower than half-life (over 100 days) of hexaconazole without CD@Fe3O4 photocatalysts.

4-Nitrophenol imprinted core-shell poly(N-isopropylacrylamide-acrylic acid)/poly(acrylic acid) microgels loaded with cadmium nanoparticles: A novel catalyst

4-nitrophenol imprinted poly(N-isopropylacrylamide-acrylic)/poly(acrylic acid) [p(NIPAM-AAc)/p(AAc)] microgels are synthesized by precipitation polymerization. 1 and 95 mol % of AAc is incorporated in core and shell of synthesized microgels respectively, so that shell can be swollen up to large extent instead of core part. Cd nanoparticles are synthesized within core using in situ reduction. Size of Cd nanoparticles and structure of microgels are analyzed by STEM, FTIR and UV–Vis spectroscopy. Series of 4-NP and its derivatives (nitroarenes and azo dyes) are reduced by using synthesized microgel as catalyst in aqueous medium. Significant difference in apparent rate constant (kapp), percentage reduction and reduction time among 4-NP and its derivatives is observed. This shows that 4-NP imprinting has affected the sieve of microgels and orientation of carboxyl groups (COOH) of AAc. Effect of solvents on catalytic reduction of 3-NP is also studied using synthesized microgel as catalyst. Significant difference in kapp, percentage reduction and reduction time of 3-NP in different solvents is also observed. 95% AAc in imprinted shell is observed as capable catalyst for reduction of 4-NP template and its derivatives. Synthesized microgel has multiple features: 4-NP imprinting, core-shell structure and 95% AAc in shell. All of these features are helped in the catalytic reduction of nitro compounds. The compounds similar to 4-NP are reduced more as compared to other compounds due to 4-NP imprinting. This shows that synthesized MIP is more effective for reduction of compounds similar to 4-NP. High mol percentage of AAc monomer within shell is facilitated the diffusion of substrates towards nanoparticles embedded in core. Possible product formation of nitroarenes and azo dyes in the presence of microgel was reported. Effect of different solvents on catalytic reduction of 3-NP is also observed.

Improved structural and dielectric properties of Cd and Ti dual doped ZnO nanoparticles

This report addressed the impact of Cadmium (Cd) and Titanium (Ti) substitution on the structural, optical and dielectric properties of Zn0.94Cd0.06−xTixO (x = 0 and 0.03). Both the samples are synthesized using the sol–gel auto combustion method and their properties are investigated using X-ray diffraction (XRD), Raman spectroscopy, UV–Visible spectroscopy and dielectric measurements. The structural study using Rietveld refinement of XRD patterns showed the presence of a single-phase hexagonal structure with the P63mc space group for both the samples. The refinement results revealed that with the increase in Ti content, both the lattice parameter and the unit cell volume increase. Shifting of the absorption edge to lower wavelength and blue shift of the bandgap are observed in the UV–Visible spectra of the Ti-doped Zn0.94Cd0.06O sample. The dielectric properties of the prepared samples were investigated by the dielectric spectrometer with varying frequencies. It has been found that dielectric constant and conductivity properties of Zn0.94Cd0.06O are enhanced via Ti substitution.

A newly isolated bacterium Comamonas sp. XL8 alleviates the toxicity of cadmium exposure in rice seedlings by accumulating cadmium

Cadmium (Cd) is a typical heavy-metal highly accumulating in crops and drinking water, thus posing a severe health risk for human health. In this study, we firstly isolated 24 Cd-resistant bacteria from the heavy-metals contaminated soil at Daye Iron Ore, in which Comamonas sp. XL8 exhibited a high resistance and strong accumulation capacity to Cd. After absorption, Comamonas sp. XL8 could biosynthesize intracellular Cd-nanoparticles (CdNPs), which has not been reported in characteristics of Comamonas genus before. We found that the gene expressions of cadA and bmtA related to Cd transportation and binding in strain XL8 were significantly upregulated with Cd exposure, suggesting that genes cadA and bmtA may contribute to the formation of CdNPs. Of particular note, the co-inoculation of Comamonas sp. XL8 and rice seedlings (Oryzae sativa L.) significantly decreased the oxidative stress-induced by Cd accumulation and subsequently alleviated toxicity of Cd exposure. Our results reveal the biochemical process of Cd accumulation in Comamonas sp. XL8 by forming CdNPs, showing that it has great potential for effective bioremediation of environmental Cd exposure.