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Luminescent switch of polysaccharide-peptide-quantum dot nanostructures for targeted-intracellular imaging of glioblastoma cells
摘要： Glioblastoma multiforme (or GBM) remains one of the deadliest types of brain cancers. Nanomedicine can offer new strategies for fighting against GBM by combining the earliest possible diagnosis with multiple options of therapy. Hence, in this work, cysteine (Cys) and Poly-L-Arginine (PA) moieties were grafted to carboxymethyl cellulose (CMC) to produce biofunctional hybridized macromolecules (CMC_Cys and CMC_PA). These polymer-peptide conjugates were used simultaneously as surface capping ligands and biofunctional modifiers for the synthesis of ternary Ag-In-S (AIS) quantum dots (AIS QDs) via a green chemical process in aqueous medium and room temperature. These core-shell supramolecular nanostructures (AIS@CMC, AIS@CMC_Cys, and AIS@CMC_PA) were tested as fluorescent nanoprobes (“OFF-ON”) for targeted bioimaging and in vitro intracellular tracking of glioblastoma cells (GBM, U-87 MG). The nanosystems were characterized for physicochemical, structural, and morphological properties by NMR, UV–Vis, PL, FTIR, TEM/EDX/SAED, zeta potential, and DLS. Cytocompatibility was evaluated by mitochondrial activity assay, and confocal laser scanning microscopy was performed for investigating the kinetics of cellular uptake. The grafting caused a noticeable reduction of surface charges, associated with a drastic photoluminescence quenching (i.e., “OFF-state”) of AIS@CMC_Cys and AIS@CMC_PA compared to unmodified AIS@CMC. This effect was smartly applied for bioimaging GBM cells and for monitoring the internalization process by intracellular tracking, which underwent strong “de-quenching” at very early incubation times (~5 min). Thus, these novel hybrid nanocolloids produced via eco-friendly scalable aqueous process show potential as responsive fluorescent bioprobes for bioimaging and tracking intracellular pathways and mechanisms as a powerful weapon for fighting against brain cancer cells.
关键词： nanoconjugates,nanomaterials,colloids,polymer-semiconductor nanoprobes,supramolecular nanoparticles,fluorescent nanoparticles
更新于2025-09-23 15:19:57
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A Short Review on Rare Earth Doped NaYF4 Upconverted Nanomaterials for Solar Cell Applications
摘要： The enhancement of upconversion luminescence (UCL) of rare earth (RE) doped upconversion nanomaterials which facilitates anti-Stokes emission is particularly important and urgently required for a broad range of applications. The fascinating properties such as anti-Stokes shifts, long life times and sharp emissions exhibits potential application in various areas. The UC is one of the exciting processes in the RE ions in which one can get the emission of high energy ultra-violet (UV) and visible (Vis) photons with the help of low energy near infrared (NIR) photons. In this mini review, we have discussed fundamental concepts of NaYF4 host for UC emission. The NaYF4 host has been selected due to its low phonon energy and composition stability. We have also demonstrated that the introduction of core shell and plasmonic nanostructure which has a critical effect on UCL. The recent advances in plasmon-enhanced UCL in RE doped NaYF4 are also noted. Finally, the recent solar cell applications of RE doped NaYF4 nanocomposite phosphor materials are introduced.
关键词： solar cell,nanomaterials,NaYF4,Rare earth
更新于2025-09-23 15:19:57
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Low dimensional metal halide perovskites and hybrids
摘要： Organic-inorganic metal halide hybrids are an important class of crystalline materials with exceptional structural and property tunability. Recently metal halide perovskites with ABX3 structure have been extensively investigated as new generation semiconductors for various optoelectronic devices, including photovoltaic cells, light emitting diodes, photodetectors, and lasers, for their exceptional optical and electronic properties. By controlling the morphological dimensionality, low dimensional metal halide perovskites, including 2D perovskite nanoplatelets, 1D perovskite nanowires, and 0D perovskite quantum dots, have been developed to exhibit distinct properties from their bulk counterparts, due to quantum size effects. Besides ABX3 perovskites, organic-inorganic metal halide hybrids, containing the same fundamental building block of metal halide octahedra (BX6), can also be assembled to possess other types of crystallographic structures. Using appropriate organic and inorganic components, low dimensional organic-inorganic metal halide hybrids with 2D, quasi-2D, corrugated-2D, 1D, and 0D structures at the molecular level have been developed and studied. Due to the strong quantum confinement and site isolation, these low dimensional metal halide hybrids at the molecular level exhibit remarkable and unique properties that are significantly different from those of ABX3 perovskites. In light of the rapid development of low dimensional metal halide perovskites and hybrids, it is indeed timely to review the recent progress in these areas. Also, there is a need to clarify the difference between morphological low dimensional metal halide perovskites and molecular level low dimensional metal halide hybrids, as currently the terminologies of low dimensional perovskites are not appropriately used in many cases. In this review article, we discuss the synthesis, characterization, application, and computational studies of low dimensional metal halide perovskites and hybrids.
关键词： Optoelectronics,Halide Perovskites,Nanomaterials,Low dimensionality,Organic metal halide hybrids
更新于2025-09-23 15:19:57
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New Insights on the Photodegradation of Caffeine in the Presence of Bio-Based Substances-Magnetic Iron Oxide Hybrid Nanomaterials
摘要： The exploitation of organic waste as a source of bio-based substances to be used in environmental applications is gaining increasing interest. In the present research, compost-derived bio-based substances (BBS-Cs) were used to prepare hybrid magnetic nanoparticles (HMNPs) to be tested as an auxiliary in advanced oxidation processes. Hybrid magnetic nanoparticles can be indeed recovered at the end of the treatment and re-used in further water purification cycles. The research aimed to give new insights on the photodegradation of caffeine, chosen as marker of anthropogenic pollution in natural waters, and representative of the contaminants of emerging concern (CECs). Hybrid magnetic nanoparticles were synthetized starting from Fe(II) and Fe(III) salts and BBS-C aqueous solution, in alkali medium, via co-precipitation. Hybrid magnetic nanoparticles were characterized via X-ray diffraction (XRD), thermo-gravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The effect of pH, added hydrogen peroxide, and dissolved oxygen on caffeine photodegradation in the presence of HMNPs was assessed. The results allow for the hypothesis that caffeine abatement can be obtained in the presence of HMNPs and hydrogen peroxide through a heterogeneous photo-Fenton mechanism. The role of hydroxyl radicals in the process was assessed examining the effect of a selective hydroxyl radical scavenger on the caffeine degradation kinetic.
关键词： hybrid nanomaterials,photo Fenton,caffeine,advanced oxidation processes,magnetic materials,bio-based substances
更新于2025-09-19 17:15:36
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Metal enhanced fluorescence biosensing: from ultra-violet towards second near-infrared window
摘要： To increase disease survival rates, there is a vital need for diagnosis at very preliminary stages. Then, low concentrations of biomarkers are present which must be effectively detected and quantified for reliable diagnosis. Fluorescent biosensing is commonly enabled through the labelling of these biomarkers with nanostructures and fluorophores. Metal Enhanced Fluorescence (MEF) is a phenomenon whereby the intensity of a fluorescent biosensor signal can be considerably enhanced by placing a metallic nanostructure and fluorophore in close proximity. Importantly, this allows for an even lower detection limit and thus earlier diagnosis. In recent years, extraordinary efforts have been made in the understanding of how the chemical and physical properties of nanomaterials may be exploited advantageously. Via precise nanoscale engineering, it is possible to optimize the optical properties of plasmonic nanomaterials, which now need to be refined and applied in diagnostics. Through MEF, the intensity of this signal can be related in direct proportion to analyte concentration, allowing for diagnosis of disease at an earlier stage than previously. This review paper outlines the potential and recent progress of applied MEF biosensors, highlighting their substantial clinical potential. MEF biosensors are presented both upon assay-based platforms and in solution, with comments on the various metallic nanoparticle morphologies available. This is explored across various emission wavelengths from ultra-violet to the second near infrared window (NIR-II), emphasising their wide applicability. Further to this, the importance of near infrared (NIR-I and NIR-II) biosensing is made clear as it allows for higher penetration in biological media. Finally, by developing multiplexing techniques, multiple and simultaneous analyses of analytes can be achieved. Through the incorporation of metal enhanced fluorescence into biosensing, it will be possible to diagnose disease more rapidly and more reliably than before, with the potential to save countless lives.
关键词： nanomaterials,biosensing,Metal Enhanced Fluorescence,fluorophores,multiplexing,near-infrared
更新于2025-09-19 17:15:36
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Ultra-Sensitive H<sub>2</sub>S Gas Sensor Based on WO<sub>3</sub> Nanocubes with Low Operating Temperature
摘要： WO3 nanostructure with nanocube morphology was synthesized through acidification of Na2WO4·2H2O, which were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Moreover, the result of the present work implied that the sensor fabricated by nanocube WO3 could detect the level of 330 ppb H2S, which is much lower than the threshold limit value of 10 ppm. Compared with other results, the nanocube WO3 sensor shows higher sensitivity, excellent selectivity and faster response/recovery to H2S. Especially, the best operating temperature of this nanocube WO3 for H2S detection is 100 oC.
关键词： H2S,Gas sensor,Nanomaterials,WO3
更新于2025-09-19 17:15:36
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Facile organic surfactant removal of various dimensionality nanomaterials using low-temperature photochemical treatment
摘要： Deep ultraviolet (DUV)-treatment is an efficient method for the removal of high-energy-barrier polymeric or aliphatic organic ligands from nanomaterials. Regardless of morphology and material, the treatment can be used for nanoparticles, nanowires, and even nanosheets. The high-energy photon irradiation from low-pressure mercury lamps or radio frequency (RF) discharge excimer lamps could enhance the electrical conductivity of various nanomaterial matrixes, such as Ag nanoparticles, Bi2Se3 nanosheets, and Ag nanowires, with the aliphatic alkyl chained ligand (oleylamine; OAm) and polymeric ligand (polyvinyl pyrrolidone; PVP) as surfactants. In particular, Ag nanoparticles (AgNPs) that are DUV-treated with polyvinyl pyrrolidone (PVP) for 90 min (50–60 °C) exhibited a sheet resistance of 0.54 Ω □?1, while thermal-treated AgNP with PVP had a sheet resistance of 7.5 kΩ □?1 at 60 °C. The simple photochemical treatment on various dimensionality nanomaterials will be an efficient sintering method for flexible devices and wearable devices with solution-processed nanomaterials.
关键词： nanomaterials,organic ligand removal,photochemical treatment,electrical conductivity,deep ultraviolet
更新于2025-09-19 17:15:36
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Colloidal Synthesis of Bulk-Bandgap Lead Selenide Nanocrystals
摘要： Lead selenide quantum dots (QDs) are low-bandgap IV-VI semiconducting nanomaterials that have been studied for a variety of applications. Their preparation using colloidal methods can create small spherical to larger cubic nanocrystals, with an upper limit of ～17 nm reported to date. Here we describe methods for preparing cubic PbSe nanocrystals over a 20–40 nm size range using a two-step procedure. Specifically, ～10 nm PbSe QDs are generated using the rapid injection method, the products from which are overcoated with additional lead and selenium precursors. The use of two lead reagents were studied; lead oleate resulted in a maximum of 20 nm cubes, while more reactive lead hexyldecanoate resulted in much larger nanomaterials with bulk bandgaps. However, PbSe samples prepared with lead hexyldecanoate also contained agglomerates. Special care must be taken when characterizing larger strained nanomaterials with X-ray powder diffraction, for which the Scherrer equation is inadequate. A more rigorous approach using the Williamson–Hall method provides characterizations that are consistent with electron microscopy analysis.
关键词： lead selenide,nanomaterials,conductivity,semiconductor,quantum dots
更新于2025-09-19 17:15:36
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Emergence of high piezoelectricity along with robust electron mobility in Janus structures in semiconducting Group IVB dichalcogenide monolayers
摘要： Piezoelectric harvesting emerging nanoelectromechanical energy. Pristine, semiconducting 1T-MX2 (M = Zr and Hf; X = S, Se, and Te) monolayers are intrinsically centrosymmetric, and hence non-piezoelectric. This inversion symmetry is broken in their Janus monolayer (non-centrosymmetric) structures, leading to the emergence of a high degree of piezoelectricity in them. This brings along a new dimension in nanoscale piezoelectricity, as the origin of this piezoelectricity is predominantly ionic in nature, in contrast to the 1H-MoS2 monolayer, where it is of electronic character. DFT calculations reveal the piezoelectric coefficient (d22 = 4.68–14.58 pm V?1) in these Janus monolayers to be much higher than that in single layer 1H-MoS2 (d11 = 2.99 pm V?1). 9% uniaxial tensile strain applied along the arm-chair direction is found to raise d22 in HfSSe Janus monolayers to 123.04 pm V?1, which reaches the level of piezoelectric coefficients in the state-of-the-art perovskites. The major contribution of the ionic component to the piezoelectric coefficient is attributable to the predominance of ionic character in the interatomic bonds in these monolayers, which arises from the decoupled band edges, i.e., no hybridization between the band edge states (chalcogen-p and metal-d). Contrarily, 1H-MX2 (M = Mo and W; X = S, Se, and Te) monolayers with coupled band edges are held together mainly by covalent bonds, resulting in the dominance of electronic contribution to piezoelectricity. The nature of band edges causes a lower deformation potential for electrons in 1T Hf and Zr based dichalcogenide monolayers and their Janus structures with respect to 1H-MX2 (M = Mo and W; X = S, Se, and Te) monolayers. This induces a much higher electron mobility in the former than in 1H-MX2 (M = Mo and W; X = S, Se, and Te) monolayers. The carrier mobility calculated using Lang et al.'s formalism [Phys. Rev. B, 2016, 94, 235306] agrees well with the experimentally measured electron mobility. Our predictive findings underscore the imminent need to synthesize these 1T-MX2 semiconducting Janus structures to induce a high level of piezoelectricity together with robust electron mobility.
关键词： nanomaterials,Piezoelectric,nanoelectromechanical energy,harvesting,emerging
更新于2025-09-19 17:15:36
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Coordination Nanosheets of Phthalocyanine as Multifunctional Platform for Imaging-Guided Synergistic Therapy of Cancer
摘要： “All-in-one” nanodrugs integrating various functionalities into one nanosystem are highly desired for cancer treatment. Coordination nanosheets as one type of two dimensional (2D) nanomaterials offer great opportunities, but lack of enough candidates. Here, a new kind of coordination nanosheets based on phthalocyanine are constructed. Manganese phthalocyanine (MnPc) tetracarboxylic acid is employed as photoactive ligand to form MnPc nanosheets; meanwhile, hyaluronic acid (HA) is coated on their surface. The obtained MnPc@HA nanosheets exhibit superior near infrared (NIR) photothermal effect with photothermal conversion efficiency of 72.3%, much higher than previously reported photothermal agents. Due to their 2D nanostructures, MnPc@HA nanosheets possess superhigh drug loading capacity for chemotherapy drug curcumin. With HA as a targeting group, the nanosheets selectively accumulated in CD-44 overexpressed tumors, followed by drug release under the control of NIR light. Moreover, MnPc@HA nanosheets with intrinsic paramagnetism can serve as T1 contrast agent for magnetic resonance imaging. The synergistic effect of phototherapy and chemotherapy endows curcumin loaded MnPc@HA nanosheets with superior tumor-eradicating efficacy. Besides, MnPc@HA nanosheets are biocompatible and safe for biomedical applications. This work provides novel insight for developing new multifunctional platforms based on 2D coordination nanosheets to synergistically combat cancer.
关键词： theranostics,drug delivery,2D nanomaterials,photothermal therapy,cancer therapy
更新于2025-09-19 17:15:36