Search Results (341)

Nanostructure-based coloration has been investigated extensively to overcome the limitations of conventional pigments and dyes. In this study, we focused on the dynamic coloration of plasmonic structures via the photothermal deformation of a metal semi-shell. However, identifying the optimal structure using this method typically requires considerable computational time. To address the high computational cost of structural optimization in dynamic plasmonic coloration, we propose an efficient method for estimating the optimal nanostructure geometry. The color gamut area was found to be influenced by both the nanosphere density and the thickness of the metal semi-shell. The optical response of deformed semi-shells, resulting from laser-induced local heating, was simulated across a range of semi-shell shapes. From these simulations, an empirical correlation was identified that links nanoparticle diameter, density, and semi-shell thickness. This correlation enables the rapid estimation of optimal parameters, thereby reducing computational demands and supporting the efficient fabrication of dynamic plasmonic color materials. Full article

Background: Wound healing and scar management remain significant challenges in dermatology and aesthetic medicine. Recent advances in regenerative medicine have introduced plant-derived exosome-like nanoparticles (PDENs) as potential therapeutic agents due to their bioactive properties. This study examines the clinical application of rose stem cell exosomes (RSCEs) in combination with established treatments for managing different types of scars. Methods: A case series of four patients with different scar etiologies (dog bite, hot oil burn, forehead trauma, and facial laser treatment complications) was treated with RSCEs in combination with microneedling (Dermapen 4.0, 0.2–0.4 mm depth) and/or thulium laser therapy (Lutronic Ultra MD, 8–14 J), or as a standalone topical treatment. All cases underwent sequential treatments over periods ranging from two to four months, with comprehensive photographic documentation of the progression. The efficacy was assessed through clinical photography and objective evaluation using the modified Vancouver Scar Scale (mVSS) and the Patient and Observer Scar Assessment Scale (POSAS), along with assessment of scar appearance, texture, and coloration. Results: All cases demonstrated progressive improvement throughout the treatment course. The dog bite scar showed significant objective improvement, with a 71% reduction in modified Vancouver Scar Scale score (from 7/13 to 2/13) and a 61% improvement in Patient and Observer Scar Assessment Scale scores after four combined treatments. The forehead trauma case exhibited similar outcomes, with a 71% improvement in mVSS score and 55–57% improvement in POSAS scores. The hot oil burn case displayed the most dramatic improvement, with a 78% reduction in mVSS score and over 70% improvement in POSAS scores, resulting in near-complete resolution without visible scarring. The facial laser complication case showed a 75% reduction in mVSS score and ~70% improvement in POSAS scores using only topical exosome application without device-based treatments. Clinical improvements across all cases included reduction in elevation, improved texture, decreased erythema, and better integration with surrounding skin. No adverse effects were reported in any of the cases. Conclusions: This preliminary case series suggests that plant-derived exosome-like nanoparticles, specifically rose stem cell exosomes (RSCEs), may enhance scar treatment outcomes when combined with microneedling and laser therapy, or even as a standalone topical treatment. The documented objective improvements, measured by standardized scar assessment scales, along with clinical enhancements in scar appearance, texture, and coloration across different scar etiologies—dog bite, burn, traumatic injury, and iatrogenic laser damage—suggest that this approach may offer a valuable addition to the current armamentarium of scar management strategies. Notably, the successful treatment of laser-induced complications using only topical exosome application demonstrates the versatility and potential of this therapeutic modality. Full article

Amyloid-β (Aβ) aggregates are considered as the important factors of Alzheimer’s disease (AD). Multifunctional materials have shown significant effects in the diagnosis and treatment of AD by modulating the aggregation of Aβ and production of reactive oxygen species (ROS). Compared to traditional surgical treatment and radiotherapy, phototherapy has the advantages, including short response time, significant efficacy, and minimal side effects in disease diagnosis and treatment. Recent studies have shown that local thermal energy or singlet oxygen generated by irradiating certain organic molecules or nanomaterials with specific laser wavelengths can effectively degrade Aβ aggregates and depress the generation of ROS, promoting progress in AD diagnosis and therapy. Herein, we outline the development of photothermal therapy (PTT) and photodynamic therapy (PDT) strategies for the diagnosis and therapy of AD by modulating Aβ aggregation. The materials mainly include organic photothermal agents or photosensitizers, polymer materials, metal nanoparticles, quantum dots, carbon-based nanomaterials, etc. In addition, compared to traditional fluorescent dyes, aggregation-induced emission (AIE) molecules have the advantages of good stability, low background signals, and strong resistance to photobleaching for bioimaging. Some AIE-based materials exhibit excellent photothermal and photodynamic effects, showing broad application prospects in the diagnosis and therapy of AD. We further summarize the advances in the detection of Aβ aggregates and phototherapy of AD using AIE-based materials. Full article

This work presents a high-performance novel photodetector based on two-dimensional boron nitride (BN) nanosheets functionalized with gold nanoparticles (Au NPs), offering ultra-broadband photoresponse from 0.25 to 5.9 μm. Operating in both photovoltaic and photoconductive modes, the device features rapid response times (<0.5 ms), high responsivity (up to 1015 mA/W at 250 nm and 2.5 V bias), and thermal stability up to 100 °C. The synthesis process involved CO₂ laser exfoliation of hexagonal boron nitride, followed by gold NP deposition via RF sputtering and thermal annealing. Structural and compositional analyses confirmed the formation of a three-dimensional network of atomically thin BN nanosheets decorated with uniformly distributed gold nanoparticles. This architecture facilitates plasmon-enhanced absorption and efficient charge separation via heterojunction interfaces, significantly boosting photocurrent generation across the deep ultraviolet (DUV), visible, near-infrared (NIR), and mid-infrared (MIR) spectral regions. First-principles calculations support the observed broadband response, confirming bandgap narrowing induced by defects in h-BN and functionalization by gold nanoparticles. The device’s self-driven operation, wide spectral response, and durability under elevated temperatures underscore its strong potential for next-generation broadband, self-powered, and wearable sensing and optoelectronic applications. Full article

Copper nanoparticles (CuNPs) are increasingly used in agriculture either alone or in combination with pesticides. Recognizing the potential hazards of CuNPs in soil environments, our study evaluated their effects on the metabolic activity of Nitrobacter winogradskyi ATCC 2539, a chemolithoautotrophic bacterium crucial for the nitrification process, which involves the oxidation of nitrite to nitrate in soil ecosystems. This study evaluated the effects of concentration ranges of CuNPs (2.5 to 162.7 mg L⁻¹), CuONPs (3.2 to 203.6 mg L⁻¹), and various pesticides (iprodione, carbendazim, and 2,4-D) and their derivatives (3,5-dichloroaniline, catechol, and 2,4-dichlorophenol) at concentrations ranging from 0.04 to 2.56 mM. CuSO₄ was also used as a control for comparative purposes. Our findings indicated that the CuNPs significantly inhibited the metabolic activity of N. winogradskyi, resulting in a reduction of up to 95% at concentrations of ≥2.5 mg L⁻¹. The CuONPs were less toxic, while the pesticides and their derivatives generally showed lower toxicity. Notably, combinations of CuNPs with pesticides or their derivatives maintained high toxicity levels comparable to those of the CuNPs alone. According to the Loewe additivity model, these effects were largely additive and primarily associated with CuNPs or CuONPs. Protein profiling using matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF)/TOF mass spectrometry (MS) revealed that carbendazim induced noticeable changes in protein profiles. These findings underscore the detrimental impacts of CuNPs and CuONPs on the metabolic activity of N. winogradskyi, posing a considerable risk to the health of agricultural soils. Overall, this research provides crucial insights into the risks associated with using CuNPs in agriculture, particularly regarding their potential threat to nitrifying microorganisms in soils. Full article

Low-surface-energy and wettability-based antifouling coatings have garnered increasing attention in marine applications owing to their environmentally friendly characteristics. However, their limited functionality often results in suboptimal long-term antifouling performance, particularly under dynamic marine conditions. To address these limitations, a polydimethylsiloxane (PDMS)-based slippery (PSL) coating was fabricated on TC4 titanium alloy by integrating surface silanization via (3-Aminopropyl)triethoxysilane (APTES), antimicrobial Ag-TiO₂ nanoparticles, laser-induced hierarchical microtextures, and silicone oil infusion. The resulting PSL coating exhibited excellent oil retention and stable interfacial slipperiness even after thermal aging. Compared with bare TC4, low-surface-energy Ag-containing coatings, Ag-containing superhydrophobic coatings, and conventional slippery liquid-infused porous surfaces (SLIPS), the PSL coating demonstrated markedly superior resistance to protein adsorption, bacterial attachment, and diatom settlement, indicating an enhanced synergistic antifouling effect. Furthermore, it significantly reduced the diatom concentration in the surrounding medium without complete eradication, underscoring its eco-friendly and non-disruptive antifouling mechanism. This study offers a scalable, durable, and environmentally benign antifouling strategy for marine surface protection. Full article

We are reporting the development of a high-performance, non-enzymatic electrochemical biosensor for selective lactate detection, integrating laser-induced graphene (LIG), gold nanoparticles (AuNPs), and a molecularly imprinted polymer (MIP) synthesized from poly(3,4-ethylenedioxythiophene) (PEDOT). The LIG electrode offers a highly porous, conductive scaffold, while electrodeposited AuNPs enhance catalytic activity and signal amplification. The PEDOT-based MIP layer, electropolymerized via cyclic voltammetry, imparts molecular specificity by creating lactate-specific binding sites. Cyclic voltammetry confirmed successful molecular imprinting and enhanced interfacial electron transfer. The resulting LIG/AuNPs/MIP biosensor demonstrated a wide linear detection range from 0.1 µM to 2500 µM, with a sensitivity of 22.42 µA/log(µM) and a low limit of detection (0.035 µM). The sensor showed excellent selectivity against common electroactive interferents such as glucose and uric acid, long-term stability, and accurate recovery in artificial saliva (>95.7%), indicating strong potential for practical application. This enzyme-free platform offers a robust and scalable strategy for continuous lactate monitoring, particularly suited for wearable devices in sports performance monitoring and critical care diagnostics. Full article

This article presents a novel method for fabricating repeatable and uniform surface-enhanced Raman scattering (SERS) substrates. The proposed method consists of two steps: (1) the fabrication of nanohole arrays using advanced femtosecond laser-induced two-photon polymerization (TPP) technology; and (2) the deposition of 9 nm thick silver nanoparticles on the nanohole arrays. The proposed nanohole arrays were optimized at the diameter, and the thickness of the silver film at two parameters. Regarding SERS substrates, a limit of detection of 10⁻¹⁰ M (rhodamine 6G) and analytical enhancement factors up to 3.5 × 10⁴ were achieved. At 1361 cm⁻¹, the relative standard deviation (RSD) of the characteristic peak was 5.5%, demonstrating a highly reproducible SERS substrate. Full article

The present study compared the free and encapsulated photosensitizer hypocrellin B (HB) in terms of photophysical-chemical properties, cellular uptake, subcellular distribution, and phototoxicity. The hydrophobic HB was encapsulated into liposomes (HB@Lipo) or poly (lactic-co-glycolic acid) nanoparticles (HB@PLGA). Encapsulation into nanocarriers exerted no obvious influence on the photophysical-chemical properties of HB, including UV-visible absorbance, fluorescence spectra, singlet oxygen (¹O₂) production capacity, and photostability. Free and encapsulated HB revealed some disparities in cellular uptake and subcellular localization patterns. In 2D-cultured B16 cells and tumor spheroids, free HB exhibited the fastest cellular uptake, while HB@PLGA had the lowest, as evidenced. Subcellular localization analysis first revealed a significant colocalization of free HB, HB@Lipo, and HB@PLGA within lipid droplets, with minimal colocalization in mitochondria and the endoplasmic reticulum. Unlike free HB and HB@Lipo, HB@PLGA exhibited strong lysosomal colocalization, indicating a unique intracellular trafficking pathway for PLGA-encapsulated HB. Upon laser irradiation, both free and encapsulated HB induced pronounced phototoxicity with substantial ROS production, confirming the robust PDT effect of HB. The photodynamic killing effect correlated with the intracellular HB content. These findings highlighted the impact of nanoformulation on HB’s cellular behavior and therapeutic performance. Full article

Thermally enhanced upconversion luminescence (UCL), also known as negative thermal quenching of UCL, denotes a continuous increase in the UCL emission intensity of a particular phosphor with a rising temperature. In recent years, the thermal enhancement of UCL has attracted extensive research attention, with numerous reports detailing this effect in phosphors characterized by varying particle sizes, architectures, and compositions. Several hypotheses have been formulated to explain the underlying mechanisms driving this thermal enhancement. This paper rigorously examines thermally enhanced UCL in fluoride nanoparticles by addressing two key questions: (1) Is the thermal enhancement of UCL an intrinsic feature of these nanoparticles? (2) Can the proposed mechanisms explaining this enhancement be unequivocally supported by the existing literature? Upon analyzing a compilation of experimental observations alongside the concurrent phenomena occurred during spectral measurements, it is postulated that thermally enhanced UCL intensity is likely a consequence of multiple extrinsic factors operating simultaneously at elevated temperatures, rather than being an intrinsic property of nanoparticles. These factors include moisture desorption, laser-induced local heating, and lattice thermal expansion. The size-dependent properties of nanoparticles, such as surface-to-volume ratio, thermal expansion coefficient, and quantum yield, are the fundamental reasons for the size-dependent thermal enhancement factor of UCL. Temperature-dependent emission spectral intensity is not a dependable indicator for assessing the thermal quenching properties of phosphors. This is because it is influenced not only by the phosphor’s quantum yield, but also by various extrinsic factors at high temperatures. The nonlinear nature of UCL further magnifies the impact of these extrinsic factors. Full article

Implant-associated infections, particularly those linked to Staphylococcus aureus (S. aureus), continue to compromise the clinical success of β-tricalcium phosphate (β-TCP) implants despite their excellent biocompatibility and osteoconductivity. This investigation aims to tackle these challenges by integrating femtosecond (fs)-laser surface processing with two complementary strategies: ion doping and functionalization with green-synthesized silver nanoparticles (AgNPs). AgNPs were produced via fs-laser photoreduction using green tea leaf extract (GTLE), noted for its anti-inflammatory and antioxidant properties. Fs-laser processing was applied to modify β-TCP scaffolds by systematically varying scanning velocities, fluences, and patterns. Lower scanning velocities generated organized nanostructures with enhanced roughness and wettability, as confirmed by scanning electron microscopy (SEM), optical profilometry, and contact angle measurements, whereas higher laser energies induced significant phase transitions between hydroxyapatite (HA) and α-tricalcium phosphate (α-TCP), as revealed by X-ray diffraction (XRD). AgNP-functionalized scaffolds demonstrated markedly superior antibacterial activity against S. aureus compared to the ion-doped variants, attributed to the synergistic interplay of nanostructure-mediated surface disruption and AgNP-induced bactericidal mechanisms. Although ion-doped scaffolds exhibited limited direct antibacterial effects, they showed concentration-dependent activity in indirect assays, likely due to controlled ion release. Both strategies promoted osteogenic differentiation of human bone marrow mesenchymal stem cells (hBM-MSCs) under defined conditions, albeit with transient cytotoxicity at higher fluences and excessive ion doping. Overall, this approach holds promise for markedly improving antibacterial efficacy and osteogenic compatibility, potentially transforming bone regeneration therapies. Full article

To enhance the performance of state-of-the-art lithium-ion batteries, high-capacity silicon is increasingly introduced as active material for anodes. Furthermore, advanced batteries with new electrode architectures—so-called 3D architectures—can provide significantly enhanced electrochemical performance compared to state-of-the-art batteries. To facilitate and speed up the architectural development, the laser-induced forward transfer (LIFT) process was applied as a digital additive manufacturing method. As polyvinylidene fluoride (PVDF), the binder commonly used in the LIFT process, is not a suitable binder for silicon-containing electrodes due to its weak binding forces, polyacrylic acid (PAA) was introduced as a binder for use in printable electrode pastes. Since water as a solvent in such pastes evaporates quickly and the corresponding printing time would be too short, glycerol was added to the solvent mixture in different amounts. The silicon in the printed electrodes reaches a specific capacity of more than 3000 mAh$·{\mathrm{g}}^{–1}$ for most of the printed anodes. To further improve the electrochemical performance of the printed electrodes, as well as the rheology of the slurries, two different conductive additives with different particle sizes were used. Full article

We demonstrate a flexible electrochemical biosensor for non-enzymatic glucose detection under different bending conditions. The novel flexible glucose sensor consists of a Cu nanoparticle (NP)/laser-induced graphene fiber (LIGF)/porous laser-induced graphene (LIG) network structure on a polyimide film. The bare LIGF/LIG electrode fabricated using an 8.9 W laser power shows a measured sheet resistance and thickness of 6.8 Ω/□ and ~420 μm, respectively. In addition, a conventional Cu NP electroplating method is used to fabricate a Cu/LIGF/LIG electrode-based glucose sensor that shows excellent glucose detection characteristics, including a sensitivity of 1438.8 µA/mM∙cm², a limit of detection (LOD) of 124 nM, and a broad linear range at an applied potential of +600 mV. Significantly, the Cu/LIGF/LIG electrode-based glucose sensor exhibits a relatively high sensitivity, low LOD, good linear detection range, and long-term stability at bending angles of 0°, 45°, 90°, 135°, and 180°. Full article

Modern applications of molecular liquid crystals span from high-resolution displays for augmented and virtual reality to miniature tunable lasers, reconfigurable microwave devices for space exploration and communication, and tunable electro-optical elements, including spatial light modulators, waveguides, lenses, light shutters, filters, and waveplates, to name a few. The tunability of these devices is achieved through electric-field-induced reorientation of liquid crystals. Because the reorientation of the liquid crystals can be altered by ions normally present in mesogenic materials in minute quantities, resulting in their electrical resistivity having finite values, the development of new ways to control the concentration of the ions in liquid crystals is very important. A promising way to enhance the electrical resistivity of molecular liquid crystals is the addition of nano-dopants to low-resistivity liquid crystals. When nanoparticles capture certain ions, they immobilize them and increase their resistivity. If properly implemented, this method can convert low-resistivity liquid crystals into high-resistivity liquid crystals. However, uncontrolled ionic contamination of the nanoparticles can significantly alter this process. In this paper, building on our previous work, we explore how physical parameters such as the size of the nanoparticles, their concentration, and their level of ionic contamination can affect the process of both enhancing and lowering the resistivity of the molecular liquid crystals. Additionally, we analyze the use of two types of nano-dopants to achieve better control over the electrical resistivity of molecular liquid crystals. Full article

Experimental protocols based on Electron Paramagnetic Resonance (EPR) and Raman spectroscopy are presented for the investigation of the Fe(II) spin transition in Cu(II)-doped 1-D spin-crossover (SCO) nanoparticles of the type [Fe_1−xCu_x(NH₂trz)₃]Br₂ where x = 0.03 and 0.06 and NH₂trz = 4-amino-1, 2, 4-triazole. The resulting nanoparticles were characterized using Transmission Electron Microscopy (TEM), Infrared (IR) spectroscopy, and powder X-ray diffraction (p-XRD). Magnetic susceptibility measurements revealed a dependence on the scan rate, with critical temperatures and hysteresis widths varying accordingly. EPR spectroscopy provided insights into the doped nanoparticles’ structural changes and spin-state transitions. The Cu(II) dopants exhibited significant g-factor anisotropy and hyperfine structure, indicative of a distorted octahedral coordination. The EPR spectra indicated that the spin transition occurs in domains populated by ions of the same spin state. Cu(II) ions show different spectral characteristics depending on whether they are in high-spin or low-spin domains of Fe(II). Changes in Raman bands induced by laser power reveal structural and electronic rearrangements during the LS to HS transition. The findings provide insights into metal–ligand interactions and the molecular mechanisms underlying the SCO process. Full article