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In this work, a simple and mild process was used to synthesize a series of 2-amino-4,6-diarylpyrimidine derivatives, 1a-1q, whose structures were verified by FTIR, 1D- and 2D-NMR, and HRMS techniques, to investigate and develop anticancer agents. Under microwave irradiation, a two-step process was carried out, consisting of aldol condensation of benzaldehydes and acetophenones to produce intermediate chalcones and ring closure condensation of chalcones and guanidine hydrochloride. Each generated compound's anticancer activity against the human chronic myelocytic leukemia K562 cancer cell line was investigated in vitro to determine the active compounds, which were subsequently evaluated for inhibiting the ABL1 tyrosine kinase. According to these findings, compound 1e demonstrated considerable inhibition against K562 cancer cells and ABL1 tyrosine kinase at IC 50 values of 8.77 ± 0.55 μM and 3.35 ± 0.58 μM, respectively. The molecular docking on wild-type and mutant type ABL1 (PDB ID 2HYY and 5MO4) investigation indicated that 1e and 1g interacted with amino acids. It formed stable hydrogen bonds and π-π linkages with crucial residues in the active site of the enzyme. Moreover, the stability of these enzyme-ligand complexes was confirmed using molecular dynamics simulations. These findings suggested that compounds 1e and 1g can be considered promising cancer treatment agents., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.) more...

In this work, ZnO nanoplates and Fe 2 O 3 nanospindles were successfully fabricated via a simple hydrothermal method using inorganic salts as precursors. The ZnO/Fe 2 O 3 hybrid was fabricated using a mechanical mixture of two different ZnO : Fe 2 O 3 weight ratios to investigate the effect of weight ratio on catalytic properties. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed that ZnO nanoplates (NPls) are about 20 nm thick with lateral dimensions of 100 × 200 nm, and Fe 2 O 3 nanospindles (NSs) are about 500 nm long and 50 nm wide. X-ray diffraction (XRD) patterns revealed the successful formation of the ZnO, Fe 2 O 3 , and ZnO/Fe 2 O 3 samples and indicated that their crystallite sizes varied from 20 to 29 nm depending on the ZnO : Fe 2 O 3 weight ratio. Ultraviolet-visible (UV-vis) spectra showed that the bandgap energies of ZnO and Fe 2 O 3 were 3.15 eV and 2.1 eV, respectively. Energy dispersive X-ray spectroscopy (EDS) results revealed the successful combination of ZnO and Fe 2 O 3 . Photocatalytic activity of the materials was evaluated through the degradation of methylene blue (MB) in aqueous solution under green light-emitting diode (GLED) irradiation. The results indicated that the ZnO/Fe 2 O 3 composite showed a remarkable enhanced degradation capacity compared to bare ZnO NPls and Fe 2 O 3 NSs. The ZnO : Fe 2 O 3 = 3 : 2 sample demonstrated the best performance among all samples under identical conditions with a degradation efficiency of 99.3% for MB after 85 min. The optimum photocatalytic activity of the sample with ZnO : Fe 2 O 3 = 3 : 2 was nearly 3.6% higher than that of the pure ZnO sample and 1.12 times more than that of the pristine Fe 2 O 3 sample. Moreover, the highest photo-degradation was obtained at a photocatalyst dosage of 0.25 g l -1 in dye solution., Competing Interests: The authors declare that they have no competing financial interests in this paper., (This journal is © The Royal Society of Chemistry.) more...

Performing effective fluorescence quenching based on a metal nanomaterial is essential to construct fluorescence sensors. Silver nanomaterials are well known as an excellent candidate for an absorber in fluorescence sensing systems. Herein, we investigated the fluorescence quenching of rhodamine B (RhB) in the presence of triangular silver nanodisks in which perfect overlap between the absorption of the absorber and the fluorescence of the fluorophore was observed. The fluorescence quenching mechanism of RhB was investigated under various excitation wavelengths, together with measurement of the fluorescence lifetime. The quenching efficiency of RhB was proportional to the wavelength excitation. Remarkably, the highest efficiency of fluorescence quenching of RhB was achieved (∼60%). The quenching mechanism was investigated and revealed to be mostly due to the inner filter effect (IFE) mechanism, without the contribution of energy transfer. This result shows a completely different story from most previous studies based on silver nanoparticles, where energy transfer was reported to play a significant role., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.) more...

CuO/ZnO nanocomposites with different components can overcome the drawbacks of previously used photocatalysts owing to their promotion in charge separation and transportation, light absorption, and the photo-oxidation of dyes. In this study, CuO nanoplates were synthesized by the hydrothermal method, while ZnO nanoparticles were fabricated by the precipitation method. A series of CuO/ZnO nanocomposites with different ZnO-to-CuO weight ratios, namely, 2 : 8, 4 : 6, 5 : 5, 6 : 4, and 8 : 2 were obtained via a mixing process. X-ray diffraction patterns confirmed the presence of hexagonal wurtzite ZnO and monoclinic CuO in the synthesized CuO/ZnO nanocomposites. Scanning electron microscopy showed the dispersion of ZnO nanoparticles on the surface of CuO nanoplates. Ultraviolet-visible absorption spectra exhibited a slight red-shift in the absorption edge of binary oxides relative to pure ZnO or CuO. All samples were employed for the photocatalytic degradation of methylene blue (MB) under visible light irradiation. The composite samples exhibited enhanced photocatalytic performance compared with pristine CuO or ZnO. This study aimed to examine the effect of the ZnO-to-CuO weight ratio on their photocatalytic performance. The results indicated that among all the synthesized nanocomposites and pristine oxides, the nanocomposite with ZnO and CuO in a proportion of 4 : 6 shows the highest photodegradation activity for the removal of MB with 93% MB photodegraded within 60 min at an initial MB concentration of 5 ppm. The photocatalytic kinetic data were described well by the pseudo-first-order model with a high correlation coefficient of 0.95. The photocatalytic mechanism of the mixed metal oxide was proposed and discussed in detail. The photodegradation characteristic of CuO/ZnO nanostructures is valuable for methylene blue degradation from aqueous solutions as well as environmental purification in various fields., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.) more...

Combining semiconductor and noble metal nanostructures into a hybrid system has shown many complementary advantages in the optical properties, making them more attractive in practical applications. Herein, we prepared a semiconductor/noble metal hybrid system composed of Ag nanoparticles decorated on ZnO nanoplates acting as a surface-enhanced Raman scattering (SERS) substrate for probing methyl red. The tuning of the optical characteristics of the hybrid system was demonstrated through the changes in the absorption, fluorescence, and Raman spectra. The formation of the local electromagnetic field at the heterostructure interface plays a pivotal role in its SERS activity. Thanks to density functional theory calculations, methyl red's vibrational modes and symmetry properties were assigned to be consistent with the contribution of the neutral trans conformer and protonated state. Then, using Herzberg-Teller-surface selection rules, these assignments strongly support the realization that the SERS mechanism based on the ZnO/Ag substrate has a significant electromagnetic contribution versus the Ag substrate in which charge transfer plays a pivotal role. To the best of our knowledge, this is the first investigation that has clarified the mechanism and advantage of semiconductor/metal (ZnO/Ag nanostructures) even over noble metals (Ag nanoparticles) in SERS applications. Moreover, the SERS behavior based on the ZnO/Ag substrate was also examined and the results indicated high sensitivity and good repeatability. more...

Decorating two-dimensional (2D) nanomaterials with nanoparticles provides an effective method to integrate their physicochemical properties. In this work, we present the hydrothermal growth process of 2D zinc oxide nanoplates (ZnO NPls), then silver nanoparticles (AgNPs) were uniformly distributed on the surface of ZnO NPls through the reduction procedure of silver nitrate with sodium borohydride to create a metal-semiconductor hybrid. The amount of AgNPs on the ZnO NPls' surface was carefully controlled by varying the volume of silver nitrate (AgNO 3 ) solution. Moreover, the effect of AgNPs on the surface-enhanced Raman scattering (SERS) property of ZnO NPls was thoroughly investigated by using methylene blue (MB) as the target molecule. After calculation, the maximum enhancement factor value for 10 -4 M of MB reached 6.2 × 10 6 for the peak at 1436 cm -1 and the limit of detection was 10 -9 M. In addition, the hybrid nanosystem could distinguish MB with good reproducibility over a wide range of concentrations, from 10 -9 to 10 -4 M. The SERS mechanism is well elucidated based on the chemical and electromagnetic mechanisms related to the synergism of ZnO and Ag in the enhancement of Raman signal. Abundant hot spots located at the gap between adjacent separate Ag nanoparticles and ZnO nanoplates which formed a strong local electromagnetic field and electron transfer between ZnO and Ag are considered to be the key factors affecting the SERS performance of our prepared ZnO/Ag substrates. In this research, we found high sensitivity of ZnO nanoplates/Ag nanoparticles in detecting MB molecules. This unique metal-semiconductor hybrid nanosystem is advantageous for the formation of Raman signals and is thus suitable for the trace detection of methylene blue., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.) more...

In the present study, a series of 6-substituted aminoindazole derivatives were designed, synthesized, and evaluated for bio-activities. The compounds were initially designed as indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors based on the structural feature of five IDO1 inhibitors, which are currently on clinical trials, and the important anticancer activity of the indazole scaffold. One of them, compound N -(4-fluorobenzyl)-1,3-dimethyl-1 H -indazol-6-amine (36), exhibited a potent anti-proliferative activity with an IC 50 value of 0.4 ± 0.3 μM in human colorectal cancer cells (HCT116). This compound also remarkably suppressed the IDO1 protein expression. In the cell-cycle studies, the suppressive activity of compound 36 in HCT116 cells was related to the G2/M cell cycle arrest. Altogether, the current findings demonstrate that compound 36 would be promising for further development as a potential anticancer agent., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.) more...

In this work, we have carried out systematic studies on the critical role of polyvinyl pyrrolidone (PVP) and citrate in the well-known chemical reduction route to synthesize silver nanodecahedra (AgND). Silver nitrate (AgNO 3 ) was used as silver source, which can be directly converted to metallic silver after being reduced by sodium borohydride (NaBH 4 ) under blue light-emitting diode (LED) irradiation ( λ max = 465 nm), and polyvinyl pyrrolidone (PVP) as a capping agent to assist the growth of AgND. The obtained products were silver nanodecahedra of excellent uniformity and stability with high efficiency and yield. The results showed that PVP acted as a capping agent to stabilize the silver nanoparticles, prolonging the initiation time required for nanodecahedra nucleation, thus inducing anisotropic growth, allowing the size and morphology of the AgND to be controlled successfully. This improved understanding allows a consistent process for the synthesis of AgND with significantly enhanced reproducibility to be developed and the formation mechanism of these nanostructures to be elucidated. This is a simple, cost-effective and easily reproducible method for creating AgND. The typical absorption maxima in the UV-vis spectroscopy of Ag seeds was λ max ∼400 nm and that of AgND was λ max ∼480 nm. The size of the prepared AgND was in the range of 60-80 nm. SEM images confirmed the uniform and high density of AgND when the concentration of PVP was 0.5 mM. The XRD pattern showed that the final product of AgND was highly crystallized. In addition, the prepared AgND can be used to detect methylene blue (MB) in a sensitive manner with good reproducibility and stability using Surface-Enhanced Raman Scattering (SERS) phenomenon. Out of the obtained products, the AgND prepared with 50 min blue LED light irradiation (AgND-50) displayed the strongest SERS signal. Interestingly, MB in diluted solution can be detected with a concentration as low as 10 -7 M (the limit of detection, LOD) and the linear dependence between SERS intensity and the MB concentration occurred in the range from 10 -7 to 10 -6 M. The enhancement factor (EF) of the SERS effect was about 1.602 × 10 6 with a MB concentration of 10 -7 M using 532 nm laser excitation., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.) more...

It is well-known that Ag-Au bimetallic nanoplates have attracted significant research interest due to their unique plasmonic properties and surface-enhanced Raman scattering (SERS). In recent years, there have been many studies on the fabrication of bimetallic nanostructures. However, controlling the shape, size, and structure of bimetallic nanostructures still has many challenges. In this work, we present the results of the synthesis of silver nanoplates (Ag NPls), and Ag-Au bimetallic core/shell and alloy nanostructures, using seed-mediated growth under green LED excitation and a gold salt (HAuCl 4 ) as a precursor of gold. The results show that the optical properties and crystal structure strongly depend on the amount of added gold salt. Interestingly, when the amount of gold( x ) in the sample was less than 0.6 μmol ( x < 0.6 μmol), the structural nature of Ag-Au was core/shell, in contrast x > 0.6 μmol gave the alloy structure. The morphology of the obtained nanostructures was investigated using the field emission scanning electron microscopy (FESEM) technique. The UV-Vis extinction spectra of Ag-Au nanostructures showed localized surface plasmon resonance (LSPR) bands in the spectral range of 402-627 nm which changed from two peaks to one peak as the amount of gold increased. Ag-Au core/shell and alloy nanostructures were utilized as surface enhanced Raman scattering (SERS) substrates to detect methylene blue (MB) (10 -7 M concentration). Our experimental observations indicated that the highest enhancement factor (EF) of about 1.2 × 10 7 was obtained with Ag-Au alloy. Our detailed investigations revealed that the Ag-Au alloy exhibited significant EF compared to pure metal Ag and Ag-Au core/shell nanostructures. Moreover, the analysis of the data revealed a linear dependence between the logarithm of concentration (log  C ) and the logarithm of SERS signal intensity (log  I ) in the range of 10 -7 -10 -4 M with a correlation coefficient ( R 2 ) of 0.994. This research helps us understand better the SERS mechanism and the application of Raman spectroscopy on a bimetallic surface., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.) more...

We investigated the effects of Mn doping on the crystal structure, phonon vibration, and magnetic properties of Bi 0.88 Sm 0.12 FeO 3ipt> ceramics. Mn doping effectively modified the rhombohedral symmetry and induced a structural transition from an R 3 c rhombohedral to Pnam orthorhombic structure. Magnetic measurements revealed a weak ferromagnetic behavior, which was related to the canted antiferromagnetic order of the Pnam structure. The cycloidal spin structure of the R 3 c phase could not be suppressed by substitution of Mn at the Fe site. Studies on the self-phase transition and electric field-induced structural transition revealed many changes in coercivity and remanent magnetization, which are believed to originate from the R 3 c / Pnam phase switching along with spin frustration. Observations of the field step-dependent hysteresis loop and the ferromagnetic-like hysteresis loop after poling in an electric field provided direct evidence of phase boundary (PB) ferromagnetism and magnetic coupling at the PB., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.) more...

A unique polyoxometalate complex made up of a tetradecanuclear nickel bisphosphonate cluster capping a {SiW9} unit has been characterized. This stable compound exhibits a high hydrogen evolution reaction photocatalytic activity under visible light irradiation via a reductive quenching mechanism. more...

Two polymers based on (3 E ,7 E )-3,7-bis(2-oxoindolin-3-ylidene)benzo[1,2- b :4,5- b ']difuran-2,6(3 H ,7 H )-dione (BIBDF) coupled with ( E )-2-(2-(thiophen-2-yl)vinyl)thiophene (TVT) or dithienylbenzothiadiazole (TBT), namely PBIBDF-TVT and PBIBDF-TBT were synthesized via the Stille coupling reaction. The effect of benzothiadiazole or vinylene-π spacer of the copolymers on optical properties, energy levels, electronic device performance and microstructure were studied. It was found that PBIBDF-TBT based OFET devices, annealed at 180 °C, showed better performance with the highest electron mobility of 2.9 × 10 -2 cm 2 V s -1 whereas PBIBDF-TVT polymer exhibited 5.0 × 10 -4 cm 2 V s -1 . The two orders of magnitude higher electron mobility of PBIBDF-TBT over PBIBDT-TVT is a clear indicator of the better charge transport ability of this polymer semiconductor arising from its higher crystallinity and better donor-acceptor interaction., Competing Interests: There is no conflicts to declare., (This journal is © The Royal Society of Chemistry.) more...

The advantages of employing an interconnected periodic ZnO morphology, i.e. an inverse opal structure, in electrodeposited ZnO/Cu2O devices are presented. The solar cells are fabricated using low cost solution based methods such as spin coating and electrodeposition. The impact of inverse opal geometry, mainly the diameter and thickness, is scrutinized. By employing 3 layers of an inverse opal structure with a 300 nm pore diameter, higher short circuit photocurrents (∼84% improvement) are observed; however the open circuit voltages decrease with increasing interfacial area. Optical simulation using a finite difference time domain method shows that the inverse opal structure modulates light propagation within the devices such that more photons are absorbed close to the ZnO/Cu2O junction. This increases the collection probability resulting in improved short circuit currents. more...

A microwave-assisted protocol was developed for the construction of 2-amino-1H-imidazole/triazole conjugates starting from the previously described 2-hydroxy-2,3-dihydro-1H-imidazo[1,2-a]pyrimidin-4-ium salts. The process involves a one-pot hydrazinolysis/Dimroth-rearrangement of these salts followed by a ligand-free copper nanoparticle-catalyzed azide-alkyne Huisgen cycloaddition. The 2-amino-1H-imidazole/triazole conjugates showed moderate to high preventive activity against biofilms of S. Typhimurium, E. coli, P. aeruginosa and S. aureus. The most active compounds had BIC50 values between 1.3 and 8 μM. A remarkable finding was that introduction of the triazole moiety into the side chain of 2-aminoimidazoles with a long (C8-C13) 2N-alkyl chain did drastically improve their activity. Conclusively, the 2-amino-1H-imidazole/triazole scaffold provides a lead structure for further design and development of novel biofilm inhibitors. more...