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P-1.3: The conductivity modulation of amorphous zinc tin oxide thin film by Ar plasma treatment
摘要： We propose a method to form low-resistance amorphous zinc tin oxide thin film (a-ZTO) by Ar plasma. The results show that the Ar plasma treatment can effectively decrease the resistivity of the a-ZTO. The ZTO film treated with Ar plasma at suitable time and moderate operating power, exhibits a low sheet resistance of 2.3 kΩ/□. With the help of PECVD-SiOx coverage layer, the sheet resistance of Ar-plasma treated ZTO is enhanced and increases only one order of magnitude after annealing at 230 ℃. As a result, an optimized Ar plasma treatment for fabrication of low-resistance a-ZTO film is presented.
关键词： amorphous zinc tin oxide,thermal stability,Ar plasma treatment,low-resistance
更新于2025-09-23 15:22:29
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Influence of Titanium Dioxide Preparation Method on Photocatalytic Degradation of Organic Dyes
摘要： Titanium catalysts (TiO2) were synthesized by three different methods. Their photocatalytic activity was validated through photodegradation of Reactive Red 45 (RR45) azo dye and Acid Blue 25 (AB25) anthraquinone dye in an aqueous solution under UV irradiation. TiO2 photocatalysts were characterized by FTIR, XRD and SEM. Photosensitivity and TiO2 activity range were characterized by UV/Vis spectroscopy. Photocatalytic validation has been made by way of determining the degree of RR45 and AB25 removal. TOC was determined as a measure of the mineralization of RR45 and AB25 by photocatalysis. The stability of TiO2 catalysts and a possibility of using them in consecutive photocatalysis cycles have also been studied. The results show that the photocatalytic efficiency depends on the crystal structure of TiO2. The size of crystallites depends on synthesis conditions. From the results of photocatalytic efficiency it is concluded that the chemical interaction between a catalyst and a dye strongly depends on the dye chemical structure.
关键词： organic dyes,wastewater treatment,photocatalysis,titanium dioxide
更新于2025-09-23 15:22:29
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Photoimmunoconjugates: novel synthetic strategies to target and treat cancer by photodynamic therapy
摘要： Photodynamic therapy (PDT) combines a photosensitizer (PS) with the physical energy of non-ionizing light to trigger cell death pathways. PDT has potential as a therapeutic modality to be used in alternative or in combination with other conventional cancer treatment protocols (e.g. surgery, chemotherapy and radiotherapy). Still, due to the lack of specificity of the current PSs to target the tumor cells, several studies have exploited their conjugation with targeting moieties. PSs conjugated with antibodies (Abs) or their fragments, able to bind antigens overexpressed in the tumors, have demonstrated potential in PDT of tumors. This review provides an overview of the most recent advances on photoimmunoconjugates (PICs) for cancer PDT, which involve the first and second-generation PSs conjugated to Abs. This is an update of our previous review “Antibodies armed with photosensitizers: from chemical synthesis to photobiological applications”, published in 2015 in Org. Biomol. Chem.
关键词： Photoimmunoconjugates,Antibody conjugation,Photosensitizers,Cancer treatment,Photodynamic therapy
更新于2025-09-23 15:22:29
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Achieving Near-Unity Photoluminescence Efficiency for Blue-violet Emitting Perovskite Nanocrystals
摘要： While the perovskite nanocrystals (NCs) have shown great promise as materials for efficient light emitting diodes (LEDs), low photoluminescence quantum yield (PLQY) of the blue-emitting perovskites is an impediment to the development of white LEDs of which blue is an essential component. Herein, we report that room temperature post-synthetic treatment of weakly blue-violet emitting (PLQY 3%) CsPbCl3 NCs with CdCl2 results in an instantaneous enhancement of the PLQY to near-unity without affecting the PL peak position (406 nm) and spectral width. The time-resolved PL and ultrafast transient absorption measurements confirm the removal of nonradiative defect states of the CsPbCl3 NCs in treated sample. The elemental composition and structural data of the treated sample reveal facile doping of Cd2+ into the crystal lattice without affecting the size and shape of the NCs. Extraordinary PLQY, high air- and photo-stability and ease of preparation of this Cd-doped CsPbCl3 make it by far the most attractive blue-emitting perovskite for development of efficient blue and white LEDs.
关键词： photoluminescence quantum yield,blue-emitting perovskites,perovskite nanocrystals,CdCl2 treatment,white LEDs
更新于2025-09-23 15:21:21
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A high therapeutic efficacy of polymeric prodrug nano-assembly for a combination of photodynamic therapy and chemotherapy
摘要： Combination of photodynamic therapy and chemotherapy has been emerging as a new strategy for cancer treatment. Conventional photosensitizer tends to aggregate in aqueous media, which causes fluorescence quenching, reduces reactive oxygen species (ROS) production, and limits its clinical application to photodynamic therapy. Traditional nanoparticle drug delivery system for chemotherapy also has its disadvantages, such as low drug loading content, drug leakage, and off-target toxicity for normal tissues. Here, we developed a reduction-sensitive co-delivery micelles TB@PMP for combinational therapy, which composed of entrapping a red aggregation-induced emission fluorogen (AIEgen) for photodynamic therapy and PMP that contains a reduction-sensitive paclitaxel polymeric prodrug for chemotherapy. AIEgen photosensitizer illustrates a much improved photostability and ROS production efficiency in aggregate state and PMP loads a high dose of paclitaxel and carries a smart stimuli-triggered drug release property. This co-delivery system provides a better option that replaces AIEgen photosensitizer for cancer diagnosis and therapy.
关键词： chemotherapy,polymeric prodrug,cancer treatment,photodynamic therapy,nanoparticles
更新于2025-09-23 15:21:21
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Enhanced photoacoustic and photothermal effect of functionalized polypyrrole nanoparticles for near-infrared theranostic treatment of tumor
摘要： Functionalized nanomaterials with near-infrared (NIR) responsive capacity are quite promising for theranostic treatment of tumors, but formation of NIR responsive nanomaterials with enhanced theranostic ability and excellent biocompatibility is still very challenging. Herein, PEGylated indocyanine green (ICG)-loaded polypyrrole nanoparticles (PPI NPs) were designed and successfully formed through selecting polydopamine as the linkage between each component, demonstrating enhanced NIR responsive theranostic ability against tumor. Combining in vitro cell study with in vivo assay, the formed PPI NPs were proved being fantastic biocompatible while effectively internalizing in HeLa cells and retaining in HeLa tumor demonstrated by in vitro flow cytometry/confocal measurement and in vivo photoacoustic imaging assay. With the guidance of photoacoustic imaging, successful photothermal ablation of tumor was achieved when treating with PPI NPs plus laser, which was much more effective than the group treated with NPs free of ICG. The greatly combined enhanced photoacoustic and photothermal effect is mainly ascribed to the functionalized polypyrrole nanoparticles, which could accumulate in tumor site more effectively with a relative longer retention time taking advantage of the nanomaterial-induced endothelial leakiness phenomenon. All these results demonstrate the designed PPI NPs possess enhanced NIR responsive property are to hold a great promise for tumor NIR theranostic applications.
关键词： polypyrrole nanoparticles,photoacoustic imaging,photothermal therapy,Functionalized nanomaterials,near-infrared (NIR) responsive,theranostic treatment
更新于2025-09-23 15:21:21
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Photoluminescence Flickering and Blinking of Single CsPbBr <sub/>3</sub> Perovskite Nanocrystals: Revealing Explicit Carrier Recombination Dynamics
摘要： In order to obtain an in-depth understanding of the dynamics and mechanism of carrier recombination in CsPbBr3 nanocrystals (NCs), we have investigated the photoluminescence (PL) of this material at the single particle level using time-tagged-time-resolved method. The study reveals two distinct types of PL fluctuations of the NCs, which are assigned to flickering and blinking. The flickering is found to be due to excess surface trap on the NCs and the flickering single particles are transformed into blinking ones with significant enhancement of PL intensity and stability on post-synthetic surface treatment. Intensity correlated lifetime analysis of the PL time-trace reveals both trap-mediated nonradiative band edge carrier recombination and positive trion recombination in single NCs. Dynamical and statistical analysis suggests a diffusive nature of the trap states to be responsible for the PL intermittency of the system. These findings throw light on the nature of the trap states, reveal the manifestation of these trap states in PL fluctuation and provide an effective way to control the dynamics of CsPbBr3 NCs.
关键词： CsPbBr3,Surface Treatment,Carrier Recombination,Photoluminescence,Nanocrystals
更新于2025-09-23 15:21:21
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Controlling surface morphology and sensitivity of granular and porous silver films for surface-enhanced Raman scattering, SERS
摘要： The design of efficient substrates for surface-enhanced Raman spectroscopy (SERS) for large-scale fabrication at low cost is an important issue in further enhancing the use of SERS for routine chemical analysis. Here, we systematically investigate the effect of different radio frequency (rf) plasmas (argon, hydrogen, nitrogen, air and oxygen plasma) as well as combinations of these plasmas on the surface morphology of thin silver films. It was found that different surface structures and different degrees of surface roughness could be obtained by a systematic variation of the plasma type and condition as well as plasma power and treatment time. The differently roughened silver surfaces act as efficient SERS substrates showing greater enhancement factors compared to as prepared, sputtered, but untreated silver films when using rhodamine B as Raman probe molecule. The obtained roughened silver films were fully characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron (XPS and Auger) and ultraviolet–visible spectroscopy (UV–vis) as well as contact angle measurements. It was found that different morphologies of the roughened Ag films could be obtained under controlled conditions. These silver films show a broad range of tunable SERS enhancement factors ranging from 1.93 × 102 to 2.35 × 105 using rhodamine B as probe molecule. The main factors that control the enhancement are the plasma gas used and the plasma conditions, i.e., pressure, power and treatment time. Altogether this work shows for the first time the effectiveness of a plasma treatment for surface roughening of silver thin films and its profound influence on the interface-controlled SERS enhancement effect. The method can be used for low-cost, large-scale production of SERS substrates.
关键词： plasma treatment,sputtering,surface-enhanced Raman spectroscopy (SERS),silver,surface roughening
更新于2025-09-23 15:21:21
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Applications of Nanotechnology in Cancer: A Literature Review of Imaging and Treatment
摘要： Recent advances in the application of nanotechnology in medicine, often referred to as nanomedicine, may revolutionize our approach to healthcare. Cancer nanotechnology is a relatively novel interdisciplinary area of comprehensive research that combines the basic sciences, like biology and chemistry, with engineering and medicine. Nanotechnology involves creating and utilizing the constructs of variable chemistry and architecture with dimensions at the nanoscale level comparable to those of biomolecules or biological vesicles in the human body. Operating with submolecular interactions, it offers the potential for unique and novel approaches with a broad spectrum of applications in cancer treatment including areas such as diagnostics, therapeutics, and prognostics. Nanotechnology also opens pathways to developing new and efficient therapeutic approaches to cancer treatment that can overcome numerous barriers posed by the human body compared to conventional approaches. Improvement in chemotherapeutic delivery through enhanced solubility and prolonged retention time has been the focus of research in nanomedicine. The submicroscopic size and flexibility of nanoparticles offer the promise of selective tumor access. Formulated from a variety of substances, nanoparticles are configured to transport myriad substances in a controlled and targeted fashion to malignant cells while minimizing the damage to normal cells. They are designed and developed to take advantage of the morphology and characteristics of a malignant tumor, such as leaky tumor vasculature, specific cell surface antigen expression, and rapid proliferation. Nanotechnology offers a revolutionary role in both diagnostics (imaging, immune-detection) and treatment (radiation therapy, chemotherapy, immunotherapy, thermotherapy, photodynamic therapy, and anti-angiogenesis). Moreover, nanoparticles may be designed to offer a multifunctional approach operating simultaneously as an effective and efficient anticancer drug as well as an imaging material to evaluate the efficacy of the drug for treatment follow-up. In recent years, nanomedicine has exhibited strong promise and progress in radically changing the approach to cancer detection and treatment.
关键词： Cancer treatment,Nanotechnology,Imaging
更新于2025-09-23 15:21:21
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A Monte Carlo based dosimetric characterization of Esteya <sup>?</sup> , an electronic surface brachytherapy unit
摘要： The purpose of this work is threefold: First, to obtain the phase-space of an electronic brachytherapy (eBT) system designed for surface skin treatments. Second, to explore the use of some efficiency enhancing (EFEN) strategies in the determination of the phase-space. Third, to use the phase-space previously obtained to perform a dosimetric characterization of the Esteya eBT system. Methods: The Monte Carlo study of the 69.5 kVp x-ray beam of the Esteya? unit (Elekta Brachytherapy, Veenendaal, The Netherlands) was performed with PENELOPE2014. The EFEN strategies included the use of variance reduction techniques and mixed Class II simulations, where transport parameters were fine-tuned. Four source models were studied varying the most relevant parameters characterizing the electron beam impinging the target: the energy spectrum (mono-energetic or Gaussian shaped), and the electron distribution over the focal spot (uniform or Gaussian shaped). Phase-spaces obtained were analyzed to detect differences in the calculated data due to the EFEN strategy or the source configuration. Depth dose curves and absorbed dose profiles were obtained for each source model and compared to experimental data previously published. Results: In our EFEN strategy, the interaction forcing variance reduction (VRIF) technique increases efficiency by a factor ~ 20. Tailoring the transport parameters values (C1 and C2) does not increase the efficiency in a significant way. Applying a universal cutoff energy EABS of 10 keV saves 84% of CPU time whilst showing negligible impact on the calculated results. Disabling the electron transport by imposing an electron energy cutoff of 70 keV (except for the target) saves an extra 8% (losing in the process 1.2% of the photons). The Gaussian energy source (FWHM = 10%, centered at the nominal kVp, homogeneous electron distribution) shows characteristic K-lines in its energy spectrum, not observed experimentally. The average photon energy using an ideal source (mono-energetic, homogeneous electron distribution) was 36.19 ± 0.09 keV, in agreement with the published measured data of 36.2 ± 0.2 keV. The use of a Gaussian-distributed electron source (mono-energetic) increases the penumbra by 50%, which is closer to the measurement results. The maximum discrepancy of the calculated percent depth dose with the corresponding measured values is 4.5% (at the phantom surface, less than 2 % beyond 1 mm depth) and 5% (for the 80% of the field) in the dose profile. Our results agree with the findings published by other authors and are consistent within the expected Type A and B uncertainties. Conclusions: Our results agree with the published measurement results within the reported uncertainties. The observed differences in PDD, dose profiles and photon spectrum come from three main sources of uncertainty: inter-machine variations, measurements and Monte Carlo calculations. It has been observed that a mono-energetic source with a Gaussian electron distribution over the focal spot is a suitable choice to reproduce the experimental data.
关键词： simulation efficiency,Monte Carlo simulation,electronic brachytherapy,surface treatment,dosimetry,x-ray source
更新于2025-09-23 15:21:21