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This review will focus on copper homeostasis in mammalian cells and on our current understanding of copper dysregulation in cancer and recent therapeutic breakthroughs using copper coordination complexes as anticancer drugs.

Modern anti-cancer drugs target DNA specifically for rapid division of malignant cells. One downside of this approach is that they also target other rapidly dividing healthy cells, such as those involved in hair growth leading to serious toxic side effects and hair loss. Therefore, it would be better to develop novel agents that address cellular signaling mechanisms unique to cancerous cells, and new research is now focussing on such approaches. Although the classical chemotherapy area involving DNA as the set target continues to produce important findings, nevertheless, a distinctly discernible emerging trend is the divergence from the cisplatin operation model that uses the metal as the primary active center of the drug. Many successful anti-cancer drugs present are associated with elevated toxicity levels. Cancers also develop immunity against most therapies and the area of cancer research can, therefore, be seen as an area with a high unaddressed need. Hence, ongoing work into cancer pathogenesis is important to create accurate preclinical tests that can contribute to the development of innovative drugs to manage and treat cancer. : Some of the emergent frontiers utilizing different approaches include nanoparticles delivery, use of quantum dots, metal complexes, tumor ablation, magnetic hypothermia and hyperthermia by use of Superparamagnetic Iron oxide Nanostructures, pathomics and radiomics, laser surgery and exosomes. : This review summarizes these new approaches in good detail, giving critical views with necessary comparisons. It also delves into what they carry for the future, including their advantages and disadvantages.

C19H22N2O2, monoclinic, P21/c (no. 14), a = 19.3063(4) Å, b = 5.83200(10) Å, c = 14.7996(3) Å, β = 92.715(1)°, V = 1664.48(6) Å3, Z = 4, R gt (F) = 0.0423, wR ref (F 2) = 0.1102, T = 100(2) K.

C20H24N2O4, monoclinic, P21/n (no. 14), a = 11.0474(3) Å, b = 6.0853(2) Å, c = 13.9881(4) Å, β = 104.271(2)°, V = 911.36(5) Å3, Z = 2, R gt (F) = 0.0290, wR ref (F 2) = 0.0728, T = 100(2) K.

New palladium (Pd)II and platinum (Pt)II complexes (C1-C5) from the Schiff base ligands, R-(phenyl)methanamine (L1), R-(pyridin-2-yl)methanamine (L2), and R-(furan-2-yl)methanamine (L3) (R-(E)-N-((1H-pyrrol-2-yl) methylene)) are herein reported. The complexes (C1-C5) were characterized by FTIR, 1H and 13C NMR, UV-vis, and microanalyses. Single-crystal X-ray crystallographic analysis was performed for the two ligands (L1-L2) and a Pt complex. Both L1 and L2 belong to P21/n monoclinic and P-1 triclinic space systems, respectively. The complex C5 belongs to the P21/c monoclinic space group. The investigated molar conductivity of the complexes in DMSO gave the range 4.0-8.8 μS/cm, suggesting neutrality, with log P values ≥ 1.2692 ± 0.004, suggesting lipophilicity. The anticancer activity and mechanism of the complexes were investigated against various human cancerous (Caco-2, HeLa, HepG2, MCF-7, and PC-3) and noncancerous (MCF-12A) cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Apopercentage assays, respectively. C5 demonstrated strong DNA-binding affinity for calf thymus DNA (CT-DNA) with a binding constant of 8.049 × 104 M-1. C3 reduced cell viability of all the six cell lines, which included five cancerous cell lines, by more than 80%. The C5 complex also demonstrated remarkably high selectivity with no cytotoxic activity toward the noncancerous breast cell line but reduced the viability of the five cancerous cell lines, which included one breast cancer cell line, by more than 60%. Further studies are required to evaluate the selective toxicity of these two complexes and to fully understand their mechanism of action.

Three new 2-pyrral amino acid Schiff base palladium (II) complexes were synthesized, characterized and their activity against six bacterial species was investigated. The ligands: Potassium 2-pyrrolidine-L-methioninate (L1), Potassium 2-pyrrolidine-L-histidinate (L2) and Potassium 2-pyrrolidine-L-tryptophanate (L3) were synthesized and reacted with dichloro(1,5-cyclooctadiene)palladium(II) to form new palladium (II) complexes C1, C2 and C3, respectively. 1H NMR, FTIR, UV–Vis, elemental analysis and conductivity measurements were used to characterize the products. The antibacterial activities of the compounds were evaluated against Gram-positive Staphylococcus aureus (S. aureus, ATCC 25923), methicillin-resistant Staphylococcus aureus (MRSA, ATCC 33591), Staphylococcus epidermidis (S. epidermidis, ATCC 12228) and Streptococcus pyogenes (S. pyogenes, ATCC 19615) and, gram-negative Pseudomonas aeruginosa (P. aeruginosa, ATCC 27853) and Klebsiella pneumoniae (K. pneumoniae, ATCC 13883) using the agar well diffusion assay and microtitre plate serial dilution method. The palladium complexes were active against the selected bacteria with the imidazole ring containing complex C2 and indole heterocyclic ring containing complex C3 showing the highest activity.

Obesity through its association with type 2 diabetes (T2D), cancer and cardiovascular diseases (CVDs), poses a serious health threat, as these diseases contribute to high mortality rates. Pharmacotherapy alone or in combination with either lifestyle modification or surgery, is reliable in maintaining a healthy body weight, and preventing progression to obesity-induced diseases. However, the anti-obesity drugs are limited by non-specificity and unsustainable weight loss effects. As such, novel and improved approaches for treatment of obesity are urgently needed. Nanotechnology-based therapies are investigated as an alternative strategy that can treat obesity and be able to overcome the drawbacks associated with conventional therapies. The review presents three nanotechnology-based anti-obesity strategies that target the white adipose tissues (WATs) and its vasculature for the reversal of obesity. These include inhibition of angiogenesis in the WATs, transformation of WATs to brown adipose tissues (BATs), and photothermal lipolysis of WATs. Compared to conventional therapy, the targeted-nanosystems have high tolerability, reduced side effects, and enhanced efficacy. These effects are reproducible using various nanocarriers (liposomes, polymeric and gold nanoparticles), thus providing a proof of concept that targeted nanotherapy can be a feasible strategy that can combat obesity and prevent its comorbidities.

Heavy metal pollution poses a grave environmental threat. Some of the most toxic metals are highly mobile and, therefore, easily transported through ground water systems, thus, affecting large areas. Over the last decade, adsorption has been greatly focused on as a strategy for contaminated water treatment. Its versatility and relative ease of application have been a major determinant of its preference. Nanosized adsorbents have high surface areas and are size tunable and, hence, have been favored in adsorption applications. The magnetic properties of nanosized magnetite (Fe3O4) have made them particularly favorable. Magnetite composites with various materials have widely been applied in the adsorptive treatment of real and synthetic water containing heavy metal pollutants. This review outlines the application of Fe3O4 nanoparticles and Fe3O4 organic composites in the adsorption of heavy metal ions in aqueous solution. The reviewed articles indicate that the formation of Fe3O4 inorganic–organic composites improves the adsorption efficiencies of the composites and improves their applicability by providing magnetic separability. The presence of Fe3O4 nanoparticles in the composite materials also provides for improved reusability of the adsorbent. Generally, the formation of these composites tends to make adsorption a more viable alternative to conventional water treatment options for heavy metal pollutants in water.

The COVID-19 global epidemic poses this generation's biggest worldwide public health challenge probably since the 1918 influenza epidemic. Recent reports on two new variants have triggered a dramatic upsurge in research to understand the pandemic, primarily focussing on the virology, triggers, clinical characteristics, and diagnostic tests including the prevention and management of the novel coronavirus. Whilst such studies are important in managing the present medical emergency, there is a need for further work to include interdependencies between the epidemic and other illnesses. This will help in developing effective approaches to treat and manage associated diseases in both the short and the long term. In this regard, people living with cancer are a subgroup that is highly vulnerable to respiratory infections and acute pneumonitis similar to the one caused by the COVID-19 virus. This is because the state of their immunity is compromised due to malignancy and the adverse effects of anticancer treatments. With annual cancer projections rising globally and an estimated 70 percent of all cancer-related deaths occurring in low- and middle-income countries, the patient population with impaired immune systems that could be adversely impacted by COVID-19 is only anticipated to rise. In this review, we delve into the challenges and health risks facing cancer patients and cancer treatment in the COVID-19 context, with suggestions into viable measures which can be taken to minimize exposure to the risk of contracting COVID-19 for this vulnerable subgroup. New mutations and the prospects offered by vaccines development and how they relate to this class of patients are also discussed. [ABSTRACT FROM AUTHOR] Copyright of Journal of Chemistry is the property of Hindawi Limited and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study presents a facile synthetic approach used to prepare CdTe/CdSe core/shell nanoparticles (NPs). The effects of reaction time on the material properties of the CdTe/CdSe NPs are reported. It was realized that the reaction time has significant impact on the CdSe shell growth on the CdTe core. Various techniques were used to characterize the as-prepared CdTe/CdSe NPs. The x-ray diffraction (XRD) was used to study the crystal structure and the possible growth of the CdSe shell on the CdTe core. The results obtained indicated the formation of zinc blende crystal structure which was transformed from a polycrystalline to single crystalline structure. The XRD pattern displayed features that are intermediate between the CdTe and CdSe, a sign of shell formation and not two separate compounds formed. This was also supported by high resolution transmission electron microscope images obtained. The crystallite sizes estimated using Scherrer formula were all less than 3 nm showing that the NPs are in quantum confinement regime. Scanning electron microscope was used to determine the surface topography while the energy x-ray dispersive spectrometer displayed the elemental composition of the as-prepared NPs. SEM and HRTEM images showed uniformly distributed spherical NPs with some agglomerations observed at longer duration of synthesis. The optical properties (photoluminescence (PL) and absorbance) investigated at different reaction times (20, 40, 60 and 80 min) presented novel features which show the formation of a thin CdSe shell on the CdTe core NPs. The PL emission wavelength was dramatically red shifted upon the growth of the CdSe shell on the CdTe core (from 541–615 nm). Other unique features of the as-grown CdTe/CdSe NPs are discussed in detail. The obtained results displayed good material properties of the CdTe/CdSe NPs suitable for use in biomaging applications.

Along with the increasing requirement for efficient organic conversions using green chemistry, there is a need to develop highly efficient and eco-friendly catalytic reaction systems. Gold nanoparticles (AuNPs)-based nanocatalysts are promising candidates for the reduction of environmental pollutants, such as nitroaromatics and dyes. This study reports on the green synthesis of AuNPs using Carpobrotus edulis (C. edulis) fruit aqueous extract (CeFE) and their catalytic activities. The CeFE induced rapid reduction of gold (III) salt to form monodispersed and spherical AuNPs, with a core and hydrodynamic sizes of 40 and 108.7 nm, respectively. CeFE alone had no effect on 4-nitrophenol, whereas incubation with methylene blue (MB) caused reduction of the peak at 665 nm. Addition of CeFE-AuNPs in the presence of NaBH4, caused the reduction of 4-nitrophenol to 4-AP, and MB to leucoMB within 10 min. These reactions followed the pseudo first-order kinetics. Therefore, biogenic CeFE-AuNPs could be used for the elimination of noxious environmental pollutants.

Obesity is a global epidemic that poses a serious health concern due to it being a risk factor for life-threatening chronic diseases, such as type 2 diabetes, cancer, and cardiovascular diseases. Pharmacotherapy remains the mainstay for the management of obesity; however, its usefulness is limited due to poor drug efficacy, non-specificity and toxic side effects. Therefore, novel approaches that could provide insights into obesity and obesity-associated diseases as well as development of novel anti-obesity treatment modalities or improvement on the existing drugs are necessary. While the ideal treatment of obesity should involve early intervention in susceptible individuals, targeted nanotherapy potentially provides a fresh perspective that might be better than the current conventional therapies. Independent studies have shown improved drug efficacy by using prohibitin (PHB)-targeted therapy in obese rodents and non-human primates, thus providing a proof of concept that targeted nanotherapy can be a feasible treatment for obesity. This review presents a brief global survey of obesity, its impact on human health, its current treatment and their limitations, and the role of angiogenesis and PHB in the development of obesity. Finally, the role and potential use of nanotechnology coupled with targeted drug delivery in the treatment of obesity are discussed.

l-cysteine capped CdTe quantum dots (QDs) were synthesized in aqueous solution in open air. In order to improve the crystallinity of the CdTe QDs, synthesis conditions were optimized. Effects of different solution pH were investigated in order to determine the optimum pH for the growth of highly crystalline CdTe QDs. X-ray diffraction patterns (XRD) for all the as-prepared samples displayed a zinc blende crystal structure. The XRD peak intensities were found to increase to a certain pH level. This was accompanied by a general increase in the crystallite sizes (3.01–3.25 nm) of the CdTe QDs as the solution pH was gradually increased from 7 to 12.5. The calculated strain in the CdTe QDs was observed to decrease with an increase in the solution pH level. The morphological studies obtained from scanning electron microscope showed clear changes in the shape of CdTe QDs with various solution pH. The shape of the QDs changed from small spherical to large flower-like and needle-like structures for various solution pH. The optical spectroscopy studies revealed that the photoluminescence emissions were shifted to longer wavelength (545–593 nm) as the pH was increased from 7 to 12.5. The ultraviolet–visible analysis displayed a red shift in the absorption peaks with an increase in the pH levels. The optical band gaps obtained from the Tauc formula displayed an inverse relation with the solution pH which could be due to increase in the QDs’ sizes with increasing pH level.

A novel prenylfuroquinoline alkaloid capensenin (1), an alkaloid confusameline (2), two furanocoumarins psolaren (3) and bergapten (4), were isolated from hexane and dichloromethane crude extracts of stem bark, leaves and fruit pericarp of Calodendrum capense. Limonin (5) was also isolated from the stem bark, while limonin diosphenol (6) was isolated from the seeds. Capensenin (1) showed weak antimicrobial activity against Bacillus subtilis, while the leaves, stem bark and fruit pericarp crude extracts exhibited activity against Staphylococcus aureus, B. subtilis and P. citrinum. Hexane pericarp extract showed slight cytotoxicity to Vero cell E199 in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The structures of the compounds were elucidated by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry and infra-red spectroscopy. Key words: Capensenin, 4-hydroxyfuroquinoline, furanocoumarin, Calodendrum capense, alkaloid, Rutaceae.

We present L -cysteine capped CdO X Te 1−X and CdTe X Se 1−X nanoparticles (NPs) prepared in one pot. The as-prepared CdO X Te 1−X NPs were found to have a hexagonal crystal structure of CdTe with a cubic phase of CdO. There was, however, change in phase to cubic type when 2 mM of Se was introduced into the CdTe at 60 min of reaction time. The average crystallite sizes obtained from X-ray diffraction analysis for CdO X Te 1−X and CdTe X Se 1−X NPs were in the range of 10–36 nm. The diffraction peaks shifted to higher diffraction angle with longer growth time. Scanning electron microscope images display change in shape and size as reaction progress. Photoluminescence (PL) emission was observed to shift from 510–566 nm and 620–653 nm for CdO X Te 1−X and CdTe X Se 1−X NPs respectively followed by variation in the peak intensities. The emission spectra displayed a good symmetry and a narrow full width at half maximum ranging from 41 to 100 nm in both cases. The absorbance analysis of the as-prepared NPs displayed well-resolved absorption bands. The optical band gaps of the as-prepared NPs were found to decrease with increase in reaction time. Reaction parameters such as pH, reaction time, reaction temperature and the molar concentration could have major effects on the optical properties of the as-prepared nanoparticles hence their need to control them.

This paper reports a facile synthesis route of high luminescent L -cysteine capped CdTe quantum dots (QDs). The effect of reaction time on the growth mechanism, optical and physical properties of the CdTe QDs was investigated in order to find the suitability of them towards optical and medical applications. The representative high-resolution transmission microscopy (HRTEM) analysis showed that the as-obtained CdTe QDs appeared as spherical particles with excellent monodispersity. The images exhibited clear lattice fringes which are indicative of good crystallinity. The X-ray diffraction (XRD) pattern displayed polycrystalline nature of the QDs which correspond well to zinc blende phase of bulk CdTe. The crystallite sizes calculated from the Scherrer equation were less than 10 nm for different reaction times which were in close agreement with the values estimated from HRTEM. An increase in reaction time improved crystallinity of the sample as explained by highest peak intensity of the XRD supported by the photoluminescence emission spectra which showed high intensity at a longer growth time. It was observed that for prolonged growth time the emission bands were red shifted from about 517–557 nm for 5–180 min of reaction time due to increase in particle sizes. Ultraviolet and visible analysis displayed well-resolved absorption bands which were red shifted upon an increase in reaction time. There was an inverse relation between the band gap and reaction time. Optical band gap decreases from 3.98 to 2.59 eV with the increase in reaction time from 15 to 180 min.

Ntevheleni Thovhogi,1 Nicole Remaliah Samantha Sibuyi,1 Martin Opiyo Onani,2 Mervin Meyer,1 Abram Madimabe Madiehe1 1Department of Science and Technology (DST)/Mintek Nanotechnology Innovation Centre, Biolabels Unit, Department of Biotechnology, 2Organometallics and Nanomaterials, Department of Chemistry, University of the Western Cape, Bellville, South Africa Background: Obesity is a worldwide epidemic affecting millions of people. The current pharmacological treatment of obesity remains limited and ineffective due to drugs’ undesirable side effects. Hence, there is a need for novel or improved strategies for long-term therapies that will help prevent the disease progression into other chronic diseases. Nanotechnology holds the future for the treatment of obesity because of its versatility, as shown by improved drug efficiency and safety in cancer clinical trials. Nano-based drug delivery systems could potentially do the same for obesity through targeted drug delivery. This study investigated the use of peptide-functionalized quantum dots (QDs) for the imaging of prohibitin (PHB)-expressing cells in vitro and in diet-induced obese rats, which could potentially be used as nanocarriers of antiobesity drugs. Methods: Cadmium (Cd)-based QDs were functionalized with an adipose homing peptide (AHP) and injected intravenously into lean and obese Wistar rats. Biodistribution of the QDs was analyzed by an IVIS® Lumina XR imaging system and inductively coupled plasma optical emission spectroscopy (ICP-OES). For in vitro studies, PHB-expressing (Caco-2 and MCF-7) and non-PHB-expressing (KMST-6 and CHO) cells were exposed to either unfunctionalized QDs (QD625) or AHP-functionalized QDs (AHP-QD625) and analyzed by fluorescence microscopy. Results: AHP-QD625 accumulated significantly in PHB-expressing cells in vitro when compared with non-PHB-expressing cells. In vivo data indicated that QD625 accumulated mainly in the reticuloendothelial system (RES) organs, while the AHP-QD625 accumulated mostly in the white adipose tissues (WATs). Conclusion: AHP-functionalized QDs were successfully and selectively delivered to the PHB-expressing cells in vitro (Caco-2 and MCF-7 cells) and in the WAT vasculature in vivo. This nanotechnology-based approach could potentially be used for dual targeted drug delivery and molecular imaging of adipose tissues in obese patients in real time. Keywords: adipose homing peptide, drug delivery, nanotechnology, prohibitin, white adipose tissue

Cadmium telluride (CdTe) has been successfully prepared by a simple wet chemical process at different reaction temperatures. Temperature is one parameter that thermodynamically plays an important role in controlling the growth rate, morphology, size and size distribution of the as-prepared nanoparticles (NPs). Effect of this parameter was investigated on the growth, structural and optical properties of CdTe NPs. It was observed that the Powder X-ray diffraction (XRD) pattern for samples prepared at 50 °C had many impurities from unreacted precursors while those prepared at > 100 °C displayed polycrystalline NPs. The XRD results revealed that the structure of the CdTe NPs was cubic with the planes (111), (220), (311) being the main observed peaks. The crystallite sizes obtained from Scherrer formula increased with the increase in growth temperature (2.86–3.62 nm grown at 50–200 °C respectively). The scanning electron microscopy micrographs showed that the morphology of the nanoparticles possessed spherical-shaped particles over the entire surface. This was further confirmed by high resolution transmission electron microscopy micrographs which also displayed increase in the particle size with an increase in the growth temperature. In the optic study, the photoluminescence (PL) spectra displayed a red shift (540–560 nm) in emission as growth temperature increased from 50 to 200 °C. The highest PL peak intensity was realized at a growth temperature of 150 °C. Absorption band maxima were observed to shift towards longer wavelength for higher growth temperatures. The optical band gap decreased with increase in the growth temperature from 2.67 to 2.08 eV for 50–200 °C respectively.

The transmission of Tuberculosis (TB) is very rapid and the burden it places on health care systems is felt globally. The effective management and prevention of this disease requires that it is detected early. Current TB diagnostic approaches, such as the culture, sputum smear, skin tuberculin, and molecular tests are time-consuming, and some are unaffordable for low-income countries. Rapid tests for disease biomarker detection are mostly based on immunological assays that use antibodies which are costly to produce, have low sensitivity and stability. Aptamers can replace antibodies in these diagnostic tests for the development of new rapid tests that are more cost effective; more stable at high temperatures and therefore have a better shelf life; do not have batch-to-batch variations, and thus more consistently bind to a specific target with similar or higher specificity and selectivity and are therefore more reliable. Advancements in TB research, in particular the application of proteomics to identify TB specific biomarkers, led to the identification of a number of biomarker proteins, that can be used to develop aptamer-based diagnostic assays able to screen individuals at the point-of-care (POC) more efficiently in resource-limited settings.

Aim: The study developed a prohibitin (PHB) targeted nanotherapy for selective induction of apoptosis in target cells. Methods: Gold nanoparticles (AuNPs) were bifunctionalized with adipose homing and proapoptotic peptides. The efficacy and mode of cell death induced by the AuNPs were investigated in vitro on three cancer cell lines. Results: The antiproliferative activity of PHB-targeted bifunctionalized AuNPs was more pronounced on cells that express the PHB receptor, and demonstrated receptor-mediated targeting and selectivity. The bifunctionalized AuNPs induced cell death by apoptosis. Conclusion: The PHB-targeted nanotherapy under study could potentially be used for treatment of diseases that are characterized by overexpression of PHB. As such, further investigations will be conducted in vivo.

Using the sol-gel technique, undoped and Cu 2+ doped ZnAl 2 O 4 samples were prepared at 0≤x≤1.24 Cu 2+ percentages. X-ray diffraction (XRD) analysis confirmed that the prepared samples were cubic and that there was no phase segregation. Energy dispersive X-rays (EDS) was then used to investigate and confirm the purity of Zn, Al, O and Cu samples with no other characteristic peaks. From the XRD spectra of Cu 2+ at different concentrations, Cu 2+ doping was found not to lead to significant lattice distortion an observation that was corroborated with density functional theory (DFT) calculations. As the Cu 2+ concentration was increased a slight shift to higher angles was recorded in XRD analysis, suggesting a larger ionic radius atom substituted by a smaller ionic radius atom. At 283 nm excitation, the doped samples were found to emit in the blue region (at 425 nm and 480 nm) of the color spectrum. Theoretically using DFT with the Hubbard correction term U, the doped system was found to emit at 435 nm which is within the emission range observed experimentally. From the calculated substitutional energies, O vac was found to have negative formation energies indicating ease of formation form in ZnAl 2 O 4 . The binding energy for Cu Zn +O vac was negative indicating that these two point defects don’t exist as pair inside ZnAl 2 O 4 .

The new compounds (5-methyl-2-thiophene-2-pyridyl(R))imine [R = methyl (L1); R = ethyl (L2)] and (5-bromo-2-thiophene-2-pyridyl(R)imine [R = methyl (L3); R = ethyl (L4)] were successfully synthesized via Schiff base condensation reaction and obtained in good yields. These potential ligands were reacted with [PdCl2(COD)] and [PdClMe(COD)] to give the corresponding complexes [PdCl2(L)] (L = L1-L4; 1–4) and [PdClMe(L)] (L = L1-L4; 5–8). All compounds were characterized by IR, 1H and 13C NMR spectroscopy, elemental analysis and mass spectrometry. The molecular structures of 1, 2, 6 and 8 were confirmed by X-ray crystallography. The complexes were evaluated as catalyst precursors for standard Heck coupling reactions and showed significant catalytic activities that could be correlated with steric and electronic influences.

CdSe flower-like nanorods (NRs) were successfully synthesized by Sol–gel technique where a simple aqueous technique was applied. The effects of different selenium (Se) concentration in the precursor solution on the material properties were studied. The X-ray diffraction (XRD) analyses show that a cubic zinc blende crystal structure was formed. Variation in the crystallite sizes were observed for different amounts of Se used in the precursor. The sizes estimated from various techniques were in the range 3–5 nm. The XRD peak intensity reached an optimum when 8 mL of 0.5 M of reduced selenium was used. The surface topography obtained from the scanning electron microscope showed densely packed and uniformly distributed flower-like rod/blade-like shaped CdSe NRs. The Fourier transform infrared spectrophotometer gave the stretching vibrations of the CdSe NRs with some bands belonging to the capping agent and the solvent. Thermal analysis conducted portrayed the 8 mL sample to be more stable than other samples at various temperatures. The photoluminescence (PL) studies displayed a red shift in the emission peaks (550–575 nm) as the selenium concentration was increased from 4 to 12 mL. This was then followed by an increase in the PL peak intensity which reached a maximum at 8 mL of Se used during the synthesis. The band gap energies calculated from the absorption spectra decreased from 3.27 to 2.79 eV with an increase in the Se concentration. The percentage transmittance of CdSe NRs varied with different amounts of Se in the precursor solution.

New thiosemicarbazone (TSC) ligands, AMT-C N-TSCH (L1), AMT-C N-TSC(CH3) (L2), CIN-C N-TSCH (L3) and CIN-C N-TSC(CH3) (L4) (AMT = 2-acetyl-5-methylthiophene, TSCH = thiosemicarbazide, TSC(CH3) = 4-methyl-3-thiosemicarbazide, CIN = cinnamaldehyde) were synthesized by condensation reaction. The reaction of [PdCODCl2] with the ligands L1, L2 and L4in the ratio 1:1 yielded complexes [Pd(L1)Cl] (C1), [Pd(L2)Cl2] (C2), and [Pd(L4)2Cl2] (C4) respectively (COD = 1,5-cyclooctadiene). The reaction of [Pd(COD)Cl2] with CIN-C N-TSCH (L3) in 1:2 metal to ligand ratio yielded the complex [Pd(L3)2] (C3). The ligands and the complexes were characterized by UV–Vis, FT-IR, NMR, elemental analysis and conductivity measurements. The ligand L1 coordinated to the metal in a tridentate fashion while L2, L3 and L4 coordinated in a bidentate fashion. The ligands L1 and L3 coordinated to the metal as thiol anions while ligand L4 coordinated via the thione sulphur. Conductivity measurements of the metal complexes in dimethyl sulfoxide showed that the chloride ions complexes C1, C2 and C4 are within the coordination spheres. The crystal structures of ligands L2 and L4 were obtained from a Bruker Smart KAPPA APEXII DUO diffractometer with graphite monochromated Mo Kαradiation (k = 0.71073 A). Cytotoxic activity of the compounds was investigated against the human cancer cell lines; Caco-2 (colon), HeLa (cervical), Hep-G2 (hepatocellular), MCF-7 (breast), PC-3 (prostate) and MCF-12A (non-cancer breast) cells. The complex C2 exhibited excellent broad spectrum growth inhibition activity against all the human cell lines tested except for the non-cancer breast cells. All the metal complexes synthesized inhibited the proliferation of human prostate cancer cell.

Substitutional energies, thermodynamic charge transition levels and optical properties of lanthanide doped anatase TiO2 has been investigated using local density approximation with the Hubbard U correction (LDA+U) within the density functional theory formalism. All the lanthanides apart from La introduced impurity states in the host band gap on doping. The calculated substitutional energies indicate that it is possible to dope TiO2 with lanthanide ions. The optimal doping percentage was predicted to be ~3% and dopant levels resulting from Ce, Nd, Sm, Gd and Tm doping were found to possess negative U characteristics. In addition the calculated thermodynamic transition levels predicted Lu as not having any possible charge transitions within the host band gap. The calculated optical absorption coefficients indicate that lanthanide doping led to optical absorption in the visible regime.

The nanocrystalline TiO2 powders with different crystallinity and phase structures were obtained by controlling hydrolysis rate and annealing temperature. Rutile phase TiO2 nanoparticles with crystallite sizes of about 80 nm, were obtained by annealing the TiO2 powders at 700 °C. The crystallite sizes of anatase phase TiO2 increases from 8 to 11 nm and band gap energy ranges from 2.49 and 3.26 eV, calculated using XRD pattern and UV–vis reflectance spectra, respectively. In agreement with change of the TiO2 band gap after different rate of hydrolysis the PL emission peak in the UV region shift slightly from 335 to 339 nm, which corresponds to the direct recombination between electrons in the conduction band and holes in the valence band. The defect related emission shifted from 376 to 385 nm with the change in the rate of hydrolysis. TiO2 nanoparticles synthesized at slow hydrolysis rate (6 ml of H2O) shows the attainment of best luminescence and maximum reflectance in the visible range. Therefore, these TiO2 nanoparticles can also be employed as coating material to develop reflectors with maximum diffuse reflectance.

The undoped and Mn-doped ZnO(1−x)Sx nano-powders were successfully synthesized by precipitation method without using any capping agent. Its structure, morphology, elemental analysis, optical and luminescence properties were determined by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), UV–vis spectroscopy (UV) and photoluminescence spectroscopy (PL). A typical SEM image of the un-doped ZnO(1−x)Sx nanoparticles exhibit flake like structures that changes to nearly spherical particles with Mn-doping. The XRD of undoped and Mn doped ZnO(1−x)Sx pattern reveals the formation of a product indexed to the hexagonal wurtzite phase of ZnS. The nanopowders have crystallite sizes estimated from XRD measurements were in the range of 10–20 nm. All the samples showed absorption maximum of ZnO(1−x)Sx at 271 nm and high transmittance in UV and visible region, respectively. The undoped ZnO(1−x)Sx nanoparticles show strong room-temperature photoluminescence with four emission bands centering at 338 nm, 384 nm, 448 nm and 705 nm that may originate to the impurity of ZnO(1−x)Sx, existence of oxide related defects. The calculated bandgap of the nanocrystalline ZnO(1−x)Sx showed a blue-shift with respect to the Mn-doping. The PL spectra of the Mn-doped samples exhibit a strong orange emission at around 594 nm attributed to the 4T1–6A1 transition of the Mn2+ ions.

A new green phosphor, La 2 Sr 3 (BO 3 ) 4 ): x % Tb 3+ was fabricated by solution-combustion method using urea as a fuel and ammonium nitrate as an oxidizer. The phosphor was characterised using Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), Energy dispersive spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectroscopy (PL. The results exhibit that La 2 Sr 3 (BO 3 ) 4 ): x % Tb 3+ phosphor has the strongest excitation at 209 nm with a full-width at half-maximum (FWHM) of 20 nm, and can emit bright green light at 545 nm under 209 nm excitation. The optimum concentration for Tb 3+ in La 2 Sr 3 (BO 3 ) 4 ): x % Tb 3+ is 0.033 mol%. The prominent green luminescence was due to the 5 D 4 – 7 F 5 transition of Tb 3+ ion. Herein, the green phosphors are promising good candidates employed in tri-color lamps.

We report a new type of indium based quantum dots which were conjugated to the magnetic Fe 2 O 3 nanoparticles. They were characterized by photoluminescence (PL), high resolution transmission electron microscopy (HRTEM), superconducting quantum interference device (SQUID) and fourier transform infra-red (FTIR). The photoluminescence characteristics of the coupled and uncoupled indium based quantum dots were investigated to determine whether the fluorescing property could be retained in the bifunctional system. Generally, the PL intensity of the quantum dots was observed to reduce significantly and with huge red shift most probably due to quenching effects for the MNPs. The average size of the coupled nanoparticles were found to range between 4 and 5 nm for the quantum dots and range of 6–13 nm for the Fe 2 O 3 magnetic nanoparticles as revealed by both HRTEM and XRD. The highest magnetic saturation reached for both bare and functionalized magnetic nanoparticles was 68.58 emu/g. The FTIR data revealed that the postulated functional groups were actually present in both the bare and functionalized nanoparticles. For instance, Fe–O was observed at around 580 cm −1 , O–H at 3432 cm −1 and thiol group at 2929 cm −1 for meso-2,3-dimercaptosuccinic acid capped Fe 2 O 3 magnetic nanoparticles. The energy dispersive spectroscopy (EDS) also confirmed that all the elements of the nanocomposite were actually present in the designed material.

Magnetic–luminescent nanoparticles have shown great promise in various biomedical applications namely: contrast agents for magnetic resonance imaging, multifunctional drug carrier system, magnetic separation of cells, cell tracking, immunoassay, and magnetic bioseparation. This experiment describes the synthesis of a nanocomposite material, which is composed of an iron oxide (Fe3O4) superparamagnetic core and an indium phosphide/zinc selenide (InP/ZnSe) quantum dot shell. The magnetic nanoparticles (MNP’s) and quantum dots (QD’s) were synthesized separately before allowing them to conjugate. The MNP’s were functionalized with a thiol-group allowing the QD shell to bind to the surface of the MNP by the formation of a thiol–metal bond. The nanocomposite was capped with 3-mercaptopropionic acid, oleylamine, β-cyclodextrin and their influence on the photoluminescence investigated. The synthesized nanocomposite was characterized with high- resolution transmission electron microscopy (HR-TEM), energy-dispersive spectroscopy (EDS), selective electron area diffraction (SAED), scanning electron microscopy (SEM), superconducting quantum interference device (SQUID), and photoluminescence. These techniques yielded particle size, morphology, dispersion, and chemical composition including luminescence and florescence.

This paper explains one pot synthesis of type II water soluble L -cysteine capped cadmium telluride (CdTe) core shell quantum dots using cadmium acetate, potassium tellurite and L -cysteine as the starting materials. The reaction was carried out in a single three necked flask without nitrogen under reflux at 100 °C. Results from PL show a sharp absorption excitonic band edge of the CdTe core with respect to the core shell which loses its shoulder during the growth of the shell on the core. The PL spectra indicate a drastic shift in emission window of the core which is simultaneously accompanied by an increase in emission intensity. X-ray diffraction pattern confirms the formation of hexagonal phase for all samples. Some difference in absorption edges were observed due to varying synthesis time of CdTe NPs. The position of the absorption band is observed to shift towards the lower wavelength side for shorter durations of synthesis.

Breast cancer tests are costly, requiring specialized instruments and highly trained operators. Serum protein biomarkers are ideal targets for the development of low cost and non-invasive point-of-care (POC) diagnostic assays such as the lateral flow immunoassay (LFIA). However, these proteins are often present at very low levels relative to other serum proteins, making it very difficult to detect the presence of the cancer biomarker proteins. There is, therefore, a need to improve the sensitivity of LFIAs. In this study, we demonstrate the functionalization of iron oxide magnetic nanoparticles using l -cysteine and conjugated to streptavidin. The functionalized MNPs-streptavidin was in turn conjugated to biotin containing an aptamer with specificity to a breast cancer biomarker protein. The complex was used to isolate MUC 1 proteins from lysates extracted from MCF-7 cells. Characterization was done to ascertain the changes in morphology before and after conjugation of the molecules to the MNPs using high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), superconducting quantum interference device (SQUID), QUBIT fluorimeter and Matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF-MS). The XRD pattern matched JCPDS no.00-039-1346 suggesting that the iron oxide synthesized is maghemite (α-Fe2O3). We quantified the isolated proteins using Qubit fluorimeter and identified them using MALDI-TOF-MS. The concentration of isolated proteins that were isolated from 6 µL of lysate and dispersed in 20 µL of PBS was determined to be 15.63 µg/mL. The concentration was determined after 3 cycles of thorough washing. The application of these MNPs in the design of LFIAs can significantly increase the sensitivity of these diagnostic devices.

Recent advancements in computation hardware and software has fueled the adoption of in silico techniques, such as density functional theory (DFT), as an investigative tool in materials' science. Hence, this study employs DFT to investigate the properties of monolayer SnS2 as function of transition metal dopant atoms. The transition metal dopants considered are T1, V, Cr, Mn, Fe, Co, Ni, Cu and Zn. Only cation substitutional doping has been considered and the doping profiles investigated were single-site and multi-site cation substitutional doping. S-rich conditions were found to favor both doping profiles with Ni and Ti not inducing any magnetic moment. This study provides insights on how in silico techniques can be adopted in material's research to evaluate dopant influences on the properties of the host.

Two new salicylaldiminato-copper(II) complexes, [ $$\hbox {Cu}(\mathbf{L}^{\mathbf{1}})_{2}$$ ] (1) and [ $$\hbox {Cu}(\mathbf{L}^{\mathbf{2}})_{2}$$ ] (2) (where $$\mathbf{HL}^{\mathbf{1}}=4$$ -tert-Butyl-2-[(thiophen-2-ylmethylimino)-methyl]-phenol and $$\mathbf{HL}^{2} = 2,4$$ -Di-tert-butyl-6-[(thiophen-2-ylmethylimino)-methyl]-phenol), endowed with a pendant thiophenyl moiety, were synthesized and characterized using standard spectroscopic techniques (FT-IR, UV-Vis, MS) and elemental analysis. Complexes 1 and 2 were unequivocally characterized by single crystal X-ray crystallography, which confirmed bidentate bis-chelation of the deprotonated - $$\mathbf{L}^{\mathbf{1}}$$ and - $$\mathbf{L}^{\mathbf{2}}$$ ligands to the copper (II) centres via the phenoxo and imine atoms forming square planar complexes. The copper(II)-hydroperoxo derivatives of 1 and 2 ([ $$(\mathbf{L}^{\mathbf{1}})_{2}\hbox {Cu}^\mathrm{II}\hbox {-OOH}$$ ] (3) and [ $$(\mathbf{L}^{\mathbf{2}})_{2}\hbox {Cu}^\mathrm{II}\hbox {-OOH}$$ ] (4)) were also synthesized and the formation of the active intermediate in solution studied. Complexes 1 and 2 were tested as catalyst precursors in cyclohexane oxidation under mild reaction conditions using hydrogen peroxide ( $$\hbox {H}_{2} \hbox {O}_{2}$$ ) as a terminal oxidant, and were found to catalyse oxidation of the substrate with yields comparable to similar mononuclear and even multinuclear copper complexes. Synopsis Synthesis, characterisation, and molecular structure of salicylaldiminato-copper(II) complexes, and their catalytic evaluation in the oxidation of cyclohexane employing hydrogen peroxide as a terminal oxidant have been studied. The complexes catalysed conversion of cyclohexane with appreciable yields.

Water-soluble cadmium telluride (CdTe) nanoparticles (NPs) were prepared using L-cystine as a capping agent. The reaction was carried out under basic conditions (at pH=11) and refluxed at 100oC for 1 h. In this work, different tellurium (Te) concentrations in the solution of L-cystine functionalized CdTe NPs were prepared at low temperature of 100oC and discussion of its effect was done in detail. The CdTe NPs were analyzed using X-ray diffraction (XRD), ultraviolet-vis and photoluminescence (PL) spectroscopy. Structural parameters estimated by XRD revealed cubic phase of CdTe at lower Te concentrations and hexagonal phase of Te emerging at higher Te concentration. XRD results showed that the NPs consisted of small CdTe nanocrystallites, 3.1-4.5 nm in size. Scanning electron microscopy was used to analyze the surface morphology of the samples and was found that it varied with different Te concentration in the aqueous solution. They consisted of spherical, rod-like and blade-like type of morphologies. The absorption thresholds of the CdTe NPs were red shifted when Te concentration was increased, due to the quantum confinement effects displayed by nanocrystalline CdTe NPs. Optical band gap energy estimated showed a decrease with an increase in the amounts of Te present while the band emissions observed in the PL spectra of CdTe NPs red shifted from 536-559 nm upon an increase in Te ratio. The PL full width at half maximum increased from 49-60 nm with increase in Cd:Te from 1:0.1 to 1:1 displaying narrow size distribution of the NPs. Highest PL intensity was realized for a 1:0.4 Cd:Te molar ratio which is an indication of improved crystallinity.