International Journal of Nanoscience

Quantum dots (QDs), a type of semiconductor nanomaterial, have drawn a lot of attention because of their exceptional optical characteristics and prospective uses in biology and medicine. However, the presence of heavy hazardous metals in typical QDs, such as Cd, Pb and Hg, has posed a significant obstacle to their use. Therefore, it is essential to look for a workable substitute that would be nontoxic and have comparable optical characteristics to the traditional QDs. It has been determined that ternary I–III–VI QDs are appropriate substitutes. They emit light in the near-infrared range and have adjustable optical characteristics. They are valuable in a variety of biological applications because of their optical characteristics and can be easily bioconjugated with biomolecules for targeted imaging. Therefore, this review concentrates on the most recent developments in the usage of aqueous CIS QDs in biological, bioconjugated with biomolecules, nanomedical and drug delivery system applications.

Solar energy is one of the main resources in our modern life. Photovoltaic panels are one of the most important technologies that make use of solar energy good because the photovoltaic cells harvest light from the sun and turn sunlight into electrical energy. This paper presents the manufacture of the solar cell from (Al/ZnO/perovskite/CuO/$p$-Psi/Al) nanostructures using the drop-casting method at a 70°C process temperature. Perovskite (Cs₄CuSb₂${\mathrm{\text{Cl}}}_{12})$ nanostructures‘ structural, optical and morphological characteristics were identified by X-ray diffraction (XRD), SEM, UV–Vis spectrophotometer and AFM. This work generated a solar cell device with the highest energy conversion efficiency (12.49%) and filling factor of 33.7%, promising to create a high-quality polycrystalline crystal. In the current study, effective hybrid Pb-free Perovskite solar cells are explained and investigated.

The green-emitting plastic scintillators with high transparence, short decay time and high quantum yield were fabricated by the modified thermal polymerization procedure. The effects of different concentrations of primary and secondary fluorescent dopants on photoluminescence performance, such as fluorescence intensity, decay time and absolute quantum yield, were investigated through orthogonal experiments. The optimal formula ratio for the plastic scintillator was that the primary dopant concentration was 0.25 wt.% and the secondary dopant concentration was 0.03 wt.%. The photoluminescence decay time of the optimal sample was 3.37 ns, which was faster than that of EJ-260 (6.57 ns) and its corresponding quantum yield was 91.57%, compared to that of EJ-260 (98.59%).

The concrete strengthening additive based on the multi-walled carbon nanotubes was synthesized under mild conditions through a radical polymerization route by the reaction of oxidized nanotubes with maleic anhydride and $\alpha$-nonene monomers. The nanotubes used as the main reinforcing component of the additive were synthesized by catalytic chemical vapor deposition (CCVD) using Fe-Co/Al₂O₃ as the catalyst. The resulting nanocomposite was characterized by structural and surface morphological aspects via transmission electron microscopy (TEM), scanning electron microscopy (SEM), FTIR, XRD and Raman techniques. Investigation of mechanical properties revealed that the obtained nanostructure is an appropriate additive material for concrete strengthening purposes with about 51.3% strengthening potential.

In this work, we synthesized lactobionic acid-decorated diselenide-linked polyethylene glycol-doxorubicin conjugate (LA-PEG-SeSe-DOX) and prepared free DOX-loaded LA-PEG-SeSe-DOX(DOX@LA-PEG-SeSe-DOX) nanoparticles for hepatoma-targeted DOX delivery. LA-PEG-SeSe-DOX can self-assemble into nanoparticles in deionized water and DOX@LA-PEG-SeSe-DOX nanoparticles were prepared by loading free DOX into LA-PEG-Se-Se-DOX nanoparticles under sonication. DOX@LA-PEG-SeSe-DOX nanoparticles have high DOX loading content of 31.3%. The dynamic scattering analysis shows that DOX@LA-PEG-SeSe-DOX nanoparticles have small size (hydrodynamic diameter $45.69\pm 0.71$nm), near neutral zeta potential, and excellent colloidal stability. The in vitro drug release study indicates that DOX@LA-PEG-SeSe-DOX nanoparticles exhibit dual redox-responsive drug release characteristics. The cellular uptake study reveals that DOX@LA-PEG-SeSe-DOX nanoparticles can be taken up by hepatoma cells by asialoglycoprotein receptor (ASGPR)-mediated pathway. Finally, DOX@LA-PEG-SeSe-DOX nanoparticles exhibit enhanced cytotoxicity against HepG2 cells as compared to LA-PEG-SeSe-DOX nanoparticles, underlining the significance of releasing free DOX for effective tumor cell proliferation inhibition. This work provides a facile and effective strategy for targeted delivery of DOX to hepatoma cells.

A biocompatible and corrosion-resistant coating was progressed by depositing a thin film of calcium titanate (CaTi${\mathrm{\text{O}}}_3)$ on CoCr-based alloy substrate using a radiofrequency magnetron plasma sputtering process to improve the characteristics of the interface between the thin-film coating and the CoCr alloy substrate. In this technique, the best power was previously observed at 225 W to get good coating film deposition properties. This power was applied to a deposited thin film of CaTiO₃ on a heated CoCr-based alloy at $100^{\circ }$C using an argon gas atmosphere with purity (99.8%) under vacuum 1.00E-02 Torr. Different deposition rates and times were used to observe nanofilm, the thicknesses of (50 nm, 80 nm, 110 nm and 140 nm). Field-emission scanning electron microscopy (FESEM) was applied to study surface morphologies. X-ray diffraction (XRD) was used to study the crystalline structure of thin films deposited. The Vickers Micro-Hardness tests were implemented on each specimen. Vitro electrochemical corrosion tests (open circuit potential, Tafel polarization curve and cyclic polarization) of the coated and uncoated specimens were done, to find the optimal state that gives excellent resistance to corrosion in a simulated body fluid environment. The results of the experiments showed that as the thickness of the thin films increased, so did the hardness measurements. An enhancement in corrosion resistance also was clearly observed at a thickness of 140 nm CaTiO₃ thin-film compared with uncoated and coated specimens at other nanothicknesses.

This research aims to prepare a nanocolloidal solution of gold and gold capped with PVA by chemical reduction method by sodium tri-citrate as a reducing agent and using gold chloride as a source of gold ions in aqueous solution at room temperature (RT). The prepared materials were diagnosed by scanning electron microscope (SEM) with the elemental composition analysis by energy dispersive X-ray (EDX), as well as the X-ray diffraction (XRD). The obtained results showed that the shape of the prepared particles is spherical with enhanced diameters close to 10 nanometers and with good scattering.

The optoelectronic response of organic perovskite solar cells (OPSCs) exhibits a variety of unique and distinguishing characteristics. In this study, OPSCs with photosensitizers, CH₃NH₃PbI₂X, where X is I, Br, or Cl, are created using TiO₂ as the electron transport material (ETM) and CuO as the hole transport material (HTM). The perovskite materials’ structural and optical characteristics, as well as the OPSCs’ ETM layers, are investigated. Next, the OPSC’s performance is evaluated. The integrated cell tester, which includes the I-V photovoltaic measurements system and the solar simulation system, was used to measure the I-V curves of the OPSCs. The photovoltaic devices with MAPbI₃ as an efficient absorption layer had the best power conversion efficiency $(\mathrm{\text{PCE}}=4.22\%)$. Measurements of the OPSC’s performance were tested at 100mW/cm² of light intensity.

Antimonous oxide (Sb₂O₃) has intriguing physical and chemical features that make it useful in various device applications, including solar cells. Pure and CuO-doped Sb₂O₃ nanofilms were prepared on glass and silicon substrates etched by laser using a thermal evaporation process in a vacuum, with doping ratios (0.02 wt.%, 0.04 wt.% and 0.06 wt.%) of CuO with a thickness of about 40 nm. The deposited nanofilms have no distinguishing peaks in X-ray diffraction analysis. Broadening of X-ray peaks shows the absence of long-range symmetry (either translational, rotational or conformational); as a consequence, the nanocrystalline structure is disorganized (disordered solids are nonamorphous materials that have lost their long-range crystalline structure). Scanning electron microscopy analysis of the surface morphology of the formed nanofilms showed that the particles were all about the same size and spread out uniformly. Atomic force microscopy scanning images showed the nanofilms’ homogeneous surface morphology with granular shape. The optical properties showed a minor increase in absorbance spectra with increasing CuO doping. Contrarily, the optical energy gap ($E_g^{\mathrm{\text{opt}}}$) was decreased by quantum confinement from 3.51 eV to 3.31 eV. As can be seen from the $I$–$V$ characteristics, the solar cell’s conversion efficiency increases to 7.62% at $P=100$ mW/cm² with a filling factor (FF) of 0.198, an open-circuit voltage of 12 V, and a short-circuit current of 3.2 mA.

Nanofibers based on the polymer mixture that was associated with poly(vinyl alcohol) (PVA) and poly(acrylamide) (PAAm) (50/50 wt.%) doped with different ratios of silver nanoparticles (Ag NPs) were successfully synthesized using electrospun method, which was performed at room temperature (RT) and high voltage (12 kV). The products were studied using techniques including scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR), X-ray diffraction (XRD) and ultraviolet–visible absorption spectroscopy. SEM results show uniform structures and a smooth surface without particles visible on the surface of the nanofibers. Also, SEM images show that the average diameter of polymer blend nanofibers is 157.40 nm and decreases with the increasing concentration of Ag NPs. The small capacity of the carbonyl group to operate as a powerful electron donor for interacting with ${\mathrm{\text{Ag}}}^{+}$ cation is shown by the fact that the FTIR signal strength decreases with increasing dopant concentration, indicating an increase in the basicity of the major functional groups. The X-ray diffraction pattern results confirm the amorphous nature (nano-crystalline) of the PVA–PAAm. The XRD results show that the crystallite size increases with the increase of the concentration of Ag and the peaks of weak intensity at a concentration of 6% agree with Ag in the cubic structure. Indirect allowed and forbidden transition optical energy gap values decreased with increasing Ag NPs content. The effect of doping on the other parameters (absorption coefficients, refraction index and extinction coefficient) of different blend behavior was investigated in detail which qualifies them for solar cell applications.