Search Results (168)

Photocatalytic redox processes significantly contribute to shaping Earth’s surface environment. Semiconductor minerals exhibiting favorable photocatalytic properties are ubiquitous on rock and soil surfaces. However, the sunlight-responsive characteristics and functions of TiO₂, an excellent photocatalytic material, within natural systems remain incompletely understood, largely due to its wide bandgap limiting solar radiation absorption. This study analyzed surface coating samples, determining their elemental composition, distribution, and mineralogy. The analysis revealed enrichment of anatase TiO₂ and β-carotene. Informed by these observations, laboratory simulations were designed to investigate the synergistic effect of β-carotene on the sunlight-responsive behavior of anatase. Results demonstrate that β-carotene-sensitized anatase exhibited a 64.4% to 66.1% increase in photocurrent compared to pure anatase. β-carotene sensitization significantly enhanced anatase’s electrochemical activity, promoting rapid electron transfer. Furthermore, it improved interfacial properties and acted as a photosensitizer, boosting photo-response characteristics. The sensitized anatase displayed a distinct absorption peak within the 425–550 nm range, with visible light absorption increasing by approximately 17.75%. This study elucidates the synergistic mechanism enhancing the sunlight response between anatase and β-carotene in natural systems and its broader environmental implications, providing new insights for research on photocatalytic redox processes within Earth’s critical zone. Full article

Background/Objectives: Magnetic iron oxide nanoparticles (IONPs), human serum albumin (HSA) and folic acid (FA) are prospective components for hybrid nanosystems for various biomedical applications. The magnetic nanosystems FA-HSA@IONPs (FAMs) containing IONPs, HSA, and FA residue are engineered in the study. Methods: Composition, stability and integrity of the coating, and peroxidase-like activity of FAMs are characterized using UV/Vis spectrophotometry (colorimetric test using o-phenylenediamine (OPD), Bradford protein assay, etc.), spectrofluorimetry, dynamic light scattering (DLS) and electron magnetic resonance (EMR). The selectivity of the FAMs accumulation in cancer cells is analyzed using flow cytometry and confocal laser scanning microscopy. Results: FAMs (d_N~55 nm by DLS) as a drug delivery platform have been administered to cancer cells (human breast adenocarcinoma MCF-7 and MDA-MB-231 cell lines) in vitro. Methylene blue, as a model photosensitizer, has been non-covalently bound to FAMs. An increase in photoinduced cytotoxicity has been found upon excitation of the photosensitizer bound to the coating of FAMs compared to the single photosensitizer at equivalent concentrations. The suitability of the nanosystems for photodynamic therapy has been confirmed. Conclusions: FAMs are able to effectively enter cells with increased folate receptor expression and thus allow antitumor photosensitizers to be delivered to cells without any loss of their in vitro photodynamic efficiency. Therapeutic and diagnostic applications of FAMs in oncology are discussed. Full article

Every year, millions of people worldwide suffer from bone tissue damage caused by bone trauma and surgical operations, as well as diseases such as osteoporosis, osteoarthritis, osteomyelitis, and periodontitis. Bone defect repair is one of the major challenges in the field of regenerative medicine. Although bone grafts are the gold standard for treating bone defects, factors such as donor sources and immune responses limit their application. Functionalized nanomaterials have become an effective means of treating bone diseases due to their good biocompatibility and osteoinductivity, anti-inflammatory, and antibacterial properties. Metal–organic frameworks (MOFs) are porous coordination polymers composed of metal ions and organic ligands, featuring unique physical properties, including a high surface area–volume ratio and porosity. In regenerative medicine, MOFs function as the functions of drug carriers, metal ion donors, nanozymes, and photosensitizers. When combined with other functional materials, they regulate cellular reactive oxygen species, macrophage phenotypic transformation, bone resorption, osteogenesis, and mineralization, providing a new paradigm for bone tissue engineering. This study reviews the classification of functionalized MOF composites in biomedicine and the application of their synthesis techniques in bone diseases. The unique in vivo and in vitro applications of MOFs in bone diseases, including osteoarthritis, osteoporosis, bone tumors, osteomyelitis, and periodontitis, are explored. Their properties include excellent drug loading and sustained release abilities, high antibacterial activity, and bone induction abilities. This review enables readers to better understand the cutting-edge progress of MOFs in bone regeneration applications, which is crucial for the design of and functional research on MOF-related nanomaterials. Full article

This paper is focused on the modification of commercial resin by using biobased fillers during stereolithography (SLA) 3D printing. This research aims to create a composite material with a matrix made of commercially available photosensitive resin modified with a filler based on secondary raw materials and materials formed as by-products in the processing of biological materials. The research determines the effect of different fillers on the tensile properties and hardness of samples printed using SLA 3D printing, and it also investigates their integrity using SEM analysis. This study aims to evaluate the feasibility of using these fillers for producing 3D-printed parts with SLA technology. The results of this study open up new possibilities for designing modified composite materials based on additive SLA 3D-printing technology using biological fillers. Within the framework of research activities, a positive effect on tensile properties and an improved interfacial interface between the matrix and the filler was demonstrated for several tested fillers. Significant increases in tensile strength of up to 22% occurred in composite systems filled with cotton flakes (CF), miscanthus (MS), walnut (WN), spruce tree (SB), wheat (WT) and eggshells (ES). Significant potential for further research activities and added value was shown by most of the tested bio-fillers. A significant contribution of the current research is the demonstration of the improved mechanical performance of photosensitive resin modified with natural fillers. Full article

Multisensory integration is fundamental for coherent perception and interaction with the environment. While cortical mechanisms of multisensory convergence are well studied, emerging evidence implicates specialized retinal ganglion cells—particularly melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs)—in crossmodal processing. This review explores how hierarchical brain networks (e.g., superior colliculus, parietal cortex) and ipRGCs jointly shape perception and behavior, focusing on their convergence in multisensory plasticity. We highlight ipRGCs as gatekeepers of environmental light cues. Their anatomical projections to multisensory areas like the superior colliculus are well established, although direct evidence for their role in human audiovisual integration remains limited. Through melanopsin signaling and subcortical projections, they may modulate downstream multisensory processing, potentially enhancing the salience of crossmodal inputs. A key theme is the spatiotemporal synergy between melanopsin and melatonin: melanopsin encodes light, while melatonin fine-tunes ipRGC activity and synaptic plasticity, potentially creating time-sensitive rehabilitation windows. However, direct evidence linking ipRGCs to audiovisual rehabilitation remains limited, with their role primarily inferred from anatomical and functional studies. Future implementations should prioritize quantitative optical metrics (e.g., melanopic irradiance, spectral composition) to standardize light-based interventions and enhance reproducibility. Nonetheless, we propose a translational framework combining multisensory stimuli (e.g., audiovisual cues) with circadian-timed melatonin to enhance recovery in visual disorders like hemianopia and spatial neglect. By bridging retinal biology with systems neuroscience, this review redefines the retina’s role in multisensory processing and offers novel, mechanistically grounded strategies for neurorehabilitation. Full article

One-dimensional (1D) nanomaterials have attracted considerable attention in the fabrication of nano-scale optoelectronic devices owing to their large specific surface areas, high surface-to-volume ratios, and directional electron transport channels. Compared to 1D metal oxide nanostructures, 1D metal sulfides have emerged as promising candidates for high-efficiency photodetectors due to their abundant surface vacancies and trap states, which facilitate oxygen adsorption and dissociation on their surfaces, thereby suppressing intrinsic carrier recombination while achieving enhanced optoelectronic performance. This review focuses on recent advancements in the performance of photodetectors fabricated using 1D binary metal sulfides as primary photosensitive layers, including nanowires, nanorods, nanotubes, and their heterostructures. Initially, the working principles of photodetectors are outlined, along with the key parameters and device types that influence their performance. Subsequently, the synthesis methods, device fabrication, and photoelectric properties of several extensively studied 1D metal sulfides and their composites, such as ZnS, CdS, SnS, Bi₂S₃, Sb₂S₃, WS₂, and SnS₂, are examined. Additionally, the current research status of 1D nanostructures of MoS₂, TiS₃, ReS₂, and In₂S₃, which are predominantly utilized as 2D materials, is explored and summarized. For systematic performance evaluation, standardized metrics encompassing responsivity, detectivity, external quantum efficiency, and response speed are comprehensively tabulated in dedicated sub-sections. The review culminates in proposing targeted research trajectories for advancing photodetection systems employing 1D binary metal sulfides. Full article

The currently used electrical energy devices for portable applications are in limited life and need of frequent recharging, it is a big bottleneck for wireless and transportation systems. The scientific community is motivated to find innovative and efficient devices to convert environmental energy into useful forms. Nanogenerator can mitigate this issue by harvesting ambient energy of different forms into useful electrical energy. Particularly flexible nanogenerators can efficiently convert ambient mechanical energy into electrical energy which can be fruitfully used for self-powered sensors and electronic appliances. Zinc oxide is an interesting photosensitive and piezoelectric material that is expected to play a vital role in the synergetic harvesting of environmental thermal, sound, mechanical, and solar energies. As ZnO can be synthesized using easy methods and materials at low cost, the conversion efficiencies of solar and other energy forms can increase considerably. ZnO is a versatile material with interesting semiconducting, optical, and piezoelectric properties; it can be used advantageously to harvest more than one type of ambient energy. The coupled semiconducting and piezoelectric properties of ZnO are attractive for fabricating nanogenerators capable of harvesting both ambient optical and mechanical energies simultaneously. These nanolevel conversion devices are much required to power remote and implantable devices without the need for additional power sources. The present review briefly discusses the principles and mechanisms of different energy harvesting abilities of ZnO nanorods and their composites by consolidating available literature. In addition, the developments taking place in nanogenerators of different kinds—such as photovoltaic, piezoelectric, pyroelectric, and triboelectrics for self-powered technology—and their progress in hybrid energy harvesting application is reviewed. Full article

W-Cu composites are widely used in the fields of switch contact materials and electronic packages because of their high hardness, high plasticity, and excellent thermal conductivity, while the traditional W-Cu composite preparation process is often accompanied by problems such as a long production cycle, difficulties in the processing of shaped parts, and difficulties in guaranteeing the uniformity. Therefore, this work developed a chemical plating technique to prepare W-20 wt.% Cu composite powder with a core–shell structure and used this powder as a raw material for powder metallurgy to solve the problem of inhomogeneity in the production of W-Cu composite by the conventional solution infiltration method. Moreover, the work also developed a high-temperature-resistant photosensitive resin, which was used as a raw material to prepare injection molds using photocuring to replace traditional steel molds. Compared to steel molds, which take about a month to prepare, 3D printed plastic molds take only a few hours, greatly reducing the production cycle. At the same time, 3D printing also provides the feasibility of the production of shaped parts. The injection molded blanks were degreased and sintered under different sintering conditions. The results show that the resultant chemically plated W-Cu composite powder has a uniform Cu coating on the surface, and the Cu forms a dense and uniform three-dimensional network in the scanning electron microscope images of each subsequent sintered specimen, while the photocuring-prepared molds were used to prepare the W-Cu shaped parts, which greatly shortened the production cycle. This preparation method enables rapid preparation of tungsten–copper composite-shaped parts with good homogeneity. Full article

Using the Bridgman technique, GaSe single crystals were obtained which were mechanically split into plane-parallel plates with a wide range of thicknesses. By heat treatment in air at 820 °C and 900 °C, for 30 min and 6 h, micro- and nanocomposite layers of Ga₂Se₃–Ga₂O₃ and β–Ga₂O₃ (native oxide) with surfaces made of nanowires/nanoribbons were obtained. The obtained composite Ga₂Se₃–Ga₂O₃ and nanostructured β–Ga₂O₃ are semiconductor materials with band gaps of 2.21 eV and 4.60 eV (gallium oxide) and photosensitivity bands in the green–red and ultraviolet-C regions that peaked at 590 nm and 262 nm. For an applied voltage of 50 V, the dark current in the photodetector based on the nanostructured β–Ga₂O₃ layer was of 8.0 × 10⁻¹³ A and increased to 9.5 × 10⁻⁸ A upon 200 s excitation with 254 nm-wavelength radiation with a power density of 15 mW/cm². The increase and decrease in the photocurrent are described by an exponential function with time constants of τ_1r = 0.92 s, τ_2r = 14.0 s, τ_1d = 2.18 s, τ_2d = 24 s, τ_1r = 0.88 s, τ_2r = 12.2 s, τ_1d = 1.69 s, and τ_2d = 16.3 s, respectively, for the photodetector based on the Ga₂Se₃–Ga₂S₃–GaSe composite. Photoresistors based on the obtained Ga₂Se₃–Ga₂O₃ composite and nanostructured β–Ga₂O₃ layers show photosensitivity bands in the spectral range of electronic absorption bands of ozone in the same green–red and ultraviolet-C regions, and can serve as ozone sensors (detectors). Full article

Micro Light Emitting Diode (Micro-LED) technology, characterized by exceptional brightness, low power consumption, fast response, and long lifespan, holds significant potential for next-generation displays, yet its commercialization hinges on resolving challenges in high-density interconnect fabrication, particularly micrometer-scale bump formation. Traditional fabrication approaches such as evaporation enable precise bump control but face scalability and cost limitations, while electroplating offers lower costs and higher throughput but suffers from substrate conductivity requirements and uneven current density distributions that compromise bump-height uniformity. Emerging alternatives include electroless plating, which achieves uniform metal deposition on non-conductive substrates through autocatalytic reactions albeit with slower deposition rates; ball mounting and dip soldering, which streamline processes via automated solder jetting or alloy immersion but struggle with bump miniaturization and low yield; and photosensitive conductive polymers that simplify fabrication via photolithography-patterned composites but lack validated long-term stability. Persistent challenges in achieving micrometer-scale uniformity, thermomechanical stability, and environmental compatibility underscore the need for integrated hybrid processes, eco-friendly manufacturing protocols, and novel material innovations to enable ultra-high-resolution and flexible Micro-LED implementations. This review systematically compares conventional and emerging methodologies, identifies critical technological bottlenecks, and proposes strategic guidelines for industrial-scale production of high-density Micro-LED displays. Full article

The mixotrophic dinoflagellate Akashiwo sanguinea is known to have acute toxic effects on multiple marine organisms, while the composition and chemical properties of its toxins remain unclear. In this study, we established a method for separation and purification of A. sanguinea toxins using chromatographic techniques. The acetone extract of A. sanguinea exhibited higher hemolytic activity and shorter incubation time compared to methanol and ethyl acetate extracts. Five fractions were obtained by solid-phase extraction (SPE), of which SPE3 (acetone/water ratio 3:2) and SPE4 (acetone/water ratio 4:1) exhibited the highest hemolytic activities and allelopathic effects. Further purification on SPE3 and SPE4 using reverse-phase high-performance liquid chromatography (RP-HPLC) coupled with a diode array detector (DAD) resulted in 11 subfractions, among which Fr4-5 displayed the strongest hemolytic activity. Nearly all active subfractions exhibited higher hemolytic activities incubated under light than those in the dark (p < 0.05), suggesting that A. sanguinea can produce both photosensitive and non-photosensitive toxins, with the former being the primary contributors to its hemolytic activity. Molecular characterization by UV-Vis, FTIR, and HRMS/MS analysis revealed that the structural features of Fr4-5 were highly consistent with porphyrin analogs and could be derived from chlorophyll c-related precursors. These findings highlight that the photosensitive toxins in A. sanguinea may serve dual roles in stress adaptation and ecological competition, potentially contributing to the formation of the blooms. Full article

Photodynamic and photothermal therapies with IR780 have gained exponential interest, and their photophysical properties have demonstrated promise for use in antitumor and antimicrobial chemotherapy. IR780 and its derivatives are valuable in labeling nanostructures with different chemical compositions for in vitro and in vivo fluorescence monitoring studies in the near-infrared (NIR) spectrum. The current literature is abundant on this topic, particularly with applications in the treatment of different types of cancer using laser illumination to produce photodynamic (PDT), photothermal (PTT), and, more recently, sonodynamic therapy (SDT) approaches for cell death. This review aims to update the state of the art concerning IR780 photosensitizer as a theranostic agent for PDT, PTT, SDT, and photoacoustic (PA) effects, and fluorescence imaging monitoring associated with different types of nanocarriers. The literature update concerns a period from 2017 to 2024, considering, more specifically, the in vivo effects found in preclinical experiments. Some aspects of the labeling stability of nanostructured systems will be discussed based on the evidence of IR780 leakage from the nanocarrier and its consequences for the reliable analysis of biological data. Full article

Flexible pressure sensors play an extremely important role in the fields of intelligent medical treatment, humanoid robots, and so on. However, the low sensitivity and the small initial capacitance still limit its application and development. At present, the method of constructing the microstructure of the dielectric layer is commonly used to improve the sensitivity of the sensor, but there are some problems, such as the complex process and inaccurate control of the microstructure. In this work, an ion composite photosensitive resin based on polyurethane acrylate and ionic liquids (ILs) was prepared. The high compatibility of the photosensitive resin and ILs was achieved by adding a chitooligosaccharide (COS) chain extender. The microstructure of the dielectric layer was optimized by digital light processing (DLP) 3D-printing. Due to the introduction of ILs to construct an electric double layer (EDL), the flexible pressure sensor exhibits a high sensitivity of 32.62 kPa⁻¹, which is 12.2 times higher than that without ILs. It also has a wide range of 100 kPa and a fast response time of 51 ms. It has a good pressure response under different pressures and can realize the demonstration application of human health. Full article

With the rapid progression of industrialization, water pollution has emerged as an increasingly critical issue, especially due to the release of organic dyes such as methylene blue (MB), which poses serious threats to both the environment and human health. Developing efficient photocatalysts to effectively degrade these pollutants is therefore of paramount importance. In this work, titanium dioxide (TiO₂) was modified with the photosensitizer hemin and the hydroxyl-rich polymer polydopamine (PDA) to enhance its photocatalytic degradation performance. Hemin and PDA function as photosensitizers, extending the light absorption of TiO₂ into the visible spectrum, reducing its bandgap energy, and effectively promoting separation of photogenerated electron–hole pairs through conjugated structures. Additionally, the strong adhesion of PDA enabled the rapid transfer and effective utilization of photogenerated electrons, while its abundant phenolic hydroxyls increased MB adsorption on the photocatalyst’s surface. Experimental results demonstrated a significant enhancement in photocatalytic activity, with the 1%PDA/3%hemin/TiO₂ composite achieving degradation rates of 91.79% under UV light and 71.53% under visible light within 120 min, representing 2.22- and 2.05-fold increases compared to unmodified TiO₂, respectively. This research presents an effective modification approach and provides important guidance for designing high-performance TiO₂-based photocatalysts aimed at environmental remediation. Full article

The effectiveness of ultraviolet-C light-emitting diodes (UVC LEDs) is currently limited by the lack of suitable encapsulation materials, restricting their use in sterilization, communication, and in vivo cancer tumor inhibition. This study evaluates various silicone oils for UVC LED encapsulation. A material aging experiment was conducted on CF1040 (octamethylcyclotetrasiloxane), HF2020 (methyl hydro polysiloxanes), and MF2020-1000 (polydimethylsiloxane) under UVC radiation for 1000 h. The analysis assessed transmittance changes and chemical composition alterations throughout the aging process. Notably, HF2020 showed an increase in transmittance before 500 h, indicating a curing process attributed to the photolysis of Si-H, leading to the formation of Si-O-Si. Further testing on 265 nm UVC LEDs, both with and without HF2020 encapsulation, showed that the encapsulated LEDs exhibited a remarkable maximum increase of 27% in radiant power compared to their unencapsulated counterparts. Additionally, these encapsulated LEDs sustained higher radiant power levels during the first 200 h of operation. Notably, its potential application in photodynamic therapy is significant; by activating photosensitizers with higher UVC exposure, it facilitates the rapid production of reactive oxygen species, leading to effective cancer cell destruction within a short timeframe. Full article