Search Results (52)

Theranostic agents enable the simultaneous diagnosis and treatment of diseases, and they are particularly useful in fluorescent imaging and cancer therapies. In this study, carbon quantum dots were synthesized via a microwave-assisted method using citric acid and bovine serum albumin (BSA) as precursors. The resulting CQDs exhibited spherical morphology, an average size of 4 nm, and an amorphous graphitic structure. FT-IR characterization revealed the presence of amide bonds and oxygenated functional groups. At the same time, optical analysis showed excitation at 320 nm and emission between 360 and 400 nm, with fluorescent stability maintained for one month. Furthermore, the CQDs demonstrated good thermal stability and photothermal efficiency, reaching temperatures above 41 °C within 15 min under NIR irradiation, with a mass loss of less than 1%. Their stability was evaluated in media with different pH levels, simulating physiological and tumor environments. While their behavior was affected under acidic conditions, their excellent photothermal conversion capacity and overall stability in triple-distilled water positioned them as promising candidates for theranostic applications in cancer, effectively combining diagnostic imaging and thermal therapy. Full article

Chromium (Cr) is a vital metal utilized in materials physics, healthcare, and various other domains. In this study, we propose an eco-friendly method for separating Cr from potassium chromate (K₂CrO₄) based on photon–phonon resonance absorption theory. Using first-principles density functional theory calculations, we obtained the Raman and infrared spectra of K₂CrO₄ and assigned the vibrational modes to the peaks observed in the experimental spectra. We confirmed that the strongest infrared absorption peak corresponds to the Cr-O bond stretching vibration theoretically located at 931 cm⁻¹. We propose employing a high-power terahertz laser at this resonant frequency for photothermal energy transfer. This approach is expected to enhance the efficiency of separating Cr from K₂CrO₄. Experimental investigations are expected in the future. Full article

The development of sustainable epoxy vitrimers with outstanding mechanical strength and facile self-healing capabilities are of great significance for prolonging the lifespan and enhancing the reliability of electronic devices. In this study, we present a castor oil-derived epoxy vitrimer (ASB–ECO) featuring dual dynamic networks enabled by rationally designed ester–imine bonds and an aromatic Schiff base-conjugated crosslinker architecture. This molecular design strategy effectively enhances the mechanical properties of vegetable oil-based vitrimers and endows them with controllable self-healing capabilities under photothermal conversion. The 1.0-ASB–ECO system demonstrates dynamic characteristics with an activation energy (Ea) of 37.25 kJ/mol and a topological freezing transition temperature (Tv) of 123.13 °C. The material exhibits a photothermal conversion efficiency (ηPT = 61.42%) and can achieve a self-healing rate of 100% under visible-light radiation. In addition, 1.0-ASB–ECO displays a dielectric constant (Dk) of 5.54 and a loss tangent (Df) of 0.025 at 106 Hz. This study on biomass-based epoxy vitrimers presents a novel approach to developing electronic materials, achieving a combination of high mechanical performance, sustainability, and photothermal self-healing properties. Full article

Desalinating seawater is a crucial method for addressing the shortage of freshwater resources. High-efficiency, low-cost, and environmentally friendly desalination technologies are key issues that urgently need to be addressed. This work used Populus tomentosa Carr. as a matrix material and prepared Populus tomentosa Carr.@Fe-GA through a complexation reaction to enhance the water evaporation rate and photothermal conversion efficiency of seawater desalination. The concentration of the impregnation solution was further refined, and the bonding mechanism along with the thermal stability of the composite photothermal material was investigated, including an assessment of their photothermal conversion efficiency. The research results indicate that the evaporation rate of water in a 3.5% NaCl solution for Populus tomentosa Carr.@Fe-GA under light intensity conditions of one sun reached 1.72 kg·m⁻²·h⁻¹, which was an increase of 44.5% compared to untreated Populus tomentosa Carr. It achieved a photothermal conversion efficiency of 95.1%, an improvement of 53.6% over untreated Populus tomentosa Carr., and maintained stability and high evaporation performance (95.4%) even after prolonged rinsing. This work realizes the functional utilization of seawater desalination with Populus tomentosa Carr. and offers a novel approach for the development and use of wood-derived photothermal material. Full article

Ab initio methods based on DFT are utilized to study the formation energy, adsorption energy, and electronic properties of pure and X-doped (X = Mo, Ti, Ni) B2-FeAl (110) surface configurations. The effect of microalloying element doping on the corrosion resistance of B2-FeAl coating to molten chlorinated salts was evaluated by the CI-NEB method. Our results show that the Ni atom preferentially occupies the position of the Fe atom, while the Mo and Ti atoms preferentially replace the Al atom in the supercell. The Cl atom tends to be adsorbed at the SB-FeAl site on a pure B2-FeAl (110) surface. The adsorption energies of a single chlorine atom at stable adsorption sites of Ni-doped B2-FeAl (110) surface are small, which means that Ni doping reduces the possibility of corrosion. The PDOS diagrams confirm that for the chlorine adsorption model of Mo-doped B2-FeAl (110) surface, strong hybridization between Mo-d, Al-p, and Fe-d orbitals occur in the energy region of −4.5~−2 eV and 0.5~2.5 eV, while in the energy range of −7.0~4.8 eV, Cl-p interacts with Mo-d and Al-s, respectively, indicating that Cl bonds with Mo and Al atom, respectively. The addition of Mo and Ni hinders the diffusion of chlorine atoms on the surface, weakens the corrosion rate of B2-FeAl in chlorinated molten salt, and improves the corrosion resistance of B2-FeAl coating. However, Ti doping promotes the migration of chlorine atoms and increases the corrosion rate of B2-FeAl in chlorinated molten salt to a certain extent. The aim of this study is to reveal the corrosion resistance mechanism of FeAl coating from the atomic level and provide a theoretical basis for the application of chloride molten salt as an efficient heat storage medium in the field of photothermal. Full article

Porphyrin’s excellent biocompatibility and modifiability make it a widely studied photoactive material. However, its large π-bond conjugated structure leads to aggregation and precipitation in physiological solutions, limiting the biomedical applications of porphyrin-based photoactive materials. It has been demonstrated through research that fabricating porphyrin molecules into nanoscale covalent organic frameworks (COFs) structures can circumvent issues such as poor dispersibility resulting from hydrophobicity, thereby significantly augmenting the photoactivity of porphyrin materials. Porphyrin-based COF materials can exert combined photodynamic and photothermal effects, circumventing the limitations of photodynamic therapy (PDT) due to hypoxia and issues in photothermal therapy (PTT) from heat shock proteins or the adverse impact of excessive heat on the protein activity of normal tissue. Furthermore, the porous structure of porphyrin COFs facilitates the circulation of oxygen molecules and reactive oxygen species and promotes sufficient contact with the lesion site for therapeutic functions. This review covers recent progress regarding porphyrin-based COFs in treating malignant tumors and venous thrombosis and for antibacterial and anti-inflammatory uses via combined PDT and PTT. By summarizing relevant design strategies, ranging from molecular design to functional application, this review provides a reference basis for the enhanced phototherapy application of porphyrin-based COFs as photoactive materials. This review aims to offer valuable insights for more effective biomedical applications of porphyrin-based COFs through the synthesis of existing experimental data, thereby paving the way for their future preclinical utilization. Full article

Surgical resection is the primary treatment for melanoma; however, preventing tumor recurrence after resection remains a significant clinical challenge. To address this, we developed a multifunctional nanocomposite hydrogel (H-CPG) composed of glucose oxidase (GOx)-coated CuS@PDA@GOx (CPG) nanoparticles, aminated hyaluronic acid (HA-ADH), and oxidized rhizomatous polysaccharides (OBSP), which are interconnected through hydrogen bonds and dynamic Schiff base linkages. In the acidic tumor micro-environment, the hydrogel releases GOx, catalyzing the production of hydrogen peroxide (H₂O₂), which enhances chemokinetic activity through a Cu²⁺-mediated Fenton-like reaction. This process generates hydroxyl radicals that intensify oxidative stress and promote macrophage polarization from the M2 to M1 phenotype. This polarization triggers the release of pro-inflammatory cytokines, thereby inhibiting tumor recurrence. Additionally, the hydrogel induces photothermal effects that help eradicate residual bacteria at the wound site. Overall, the H-CPG hydrogel offers a dual mechanism to prevent melanoma recurrence and reduce resistance to monotherapy, presenting a promising strategy for postoperative tumor management. Full article

As a novel therapeutic approach, photothermal therapy (PTT) combined with chemotherapy can synergistically produce antitumor effects. Herein, dithiodipropionic acid (DTDP) was used as a donor of disulfide bonds sensitive to the tumor microenvironment for establishing chemical bonding between the photosensitizer indocyanine green amino (ICG-NH₂) and acidified single-walled carbon nanotubes (CNTs). The CNT surface was then coated with conjugates (HD) formed by the targeted modifier hyaluronic acid (HA) and 1,2-tetragacylphosphatidyl ethanolamine (DMPE). After doxorubicin hydrochloride (DOX), used as the model drug, was loaded by CNT carriers, functional nano-delivery systems (HD/CNTs-SS-ICG@DOX) were developed. Nanosystems can effectively induce tumor cell (MCF-7) death in vitro by accelerating cell apoptosis, affecting cell cycle distribution and reactive oxygen species (ROS) production. The in vivo antitumor activity results in tumor-bearing model mice, further verifying that HD/CNTs-SS-ICG@DOX inhibited tumor growth most significantly by mediating a synergistic effect between chemotherapy and PTT, while various functional nanosystems have shown good biological tissue safety. In conclusion, the composite CNT delivery systems developed in this study possess the features of high biocompatibility, targeted delivery, and responsive drug release, and can achieve the efficient coordination of chemotherapy and PTT, with broad application prospects in cancer treatment. Full article

The mechanism of the combined process of ion beam sputtering (IBS) and HF acid etching on the chemical structure defects of fused silica and its laser damage resistance performance were investigated in this paper. During the removal process of surface material, the sputtering effect causes lattice atoms to flee their native space locations, and a large amount of unsaturated chemical structures are produced on the silica surface, which improves the chemical activity of Si and O atoms, accelerates the chemical reaction process between surface atoms and water molecules, increases the content of hydroxyl groups (OH-) in the shallow layer, and enhances the photothermal weak absorption intensity. However, the increase in hydroxyl content weakens the binding strength of silicon–oxygen bonds, destroys the spatial network structure of silica bulk, and reduces its mechanical strength, resulting in a decrease in its laser damage resistance performance. The paper reveals for the first time the mechanism by which IBS changes the structure characteristics of silica material, accelerates the surface hydroxylation process, and thereby reduces the laser damage resistance performance. This work provides technical guidance for effectively suppressing chemical structure defects on silica surfaces and improving the laser damage resistance performance of optical components under high-flux laser irradiation. Full article

Shape-shifting polymers are widely used in various fields such as intelligent switches, soft robots and sensors, which require both multiple stimulus-response functions and qualified mechanical strength. In this study, a novel near-infrared-light (NIR)-responsible shape-shifting hydrogel system was designed and fabricated through embedding vinylsilane-modified carbon nanotubes (CNTs) into particle double-network (P-DN) hydrogels by micellar copolymerisation. The dispersed brittle Poly(sodium 2-acrylamido-2-methylpropane-1-sulfonate) (PNaAMPS) network of the microgels can serve as sacrificial bonds to toughen the hydrogels, and the CNTs endow it with NIR photothermal conversion ability. The results show that the CNTs embedded in the P-DN hydrogels present excellent mechanical strength, i.e., a fracture strength of 312 kPa and a fracture strain of 357%. Moreover, an asymmetric bilayer hydrogel, where the active layer contains CNTs, can achieve 0°–110° bending deformation within 10 min under NIR irradiation and can realise complex deformation movement. This study provides a theoretical and experimental basis for the design and manufacture of photoresponsive soft actuators. Full article

Currently, the obvious side effects of anti-tumor drugs, premature drug release, and low tumor penetration of nanoparticles have largely reduced the therapeutic effects of chemotherapy. A drug delivery vehicle (MCN-SS-GQDs) was designed innovatively. For this, the mesoporous carbon nanoparticles (MCN) with the capabilities of superior photothermal conversion efficiency and high loading efficiency were used as the skeleton structure, and graphene quantum dots (GQDs) were gated on the mesopores via disulfide bonds. The doxorubicin (DOX) was used to evaluate the pH-, GSH-, and NIR-responsive release performances of DOX/MCN-SS-GQDs. The disulfide bonds of MCN-SS-GQDs can be ruptured under high glutathione concentration in the tumor microenvironment, inducing the responsive release of DOX and the detachment of GQDs. The local temperature of a tumor increases significantly through the photothermal conversion of double carbon materials (MCN and GQDs) under near-infrared light irradiation. Local hyperthermia can promote tumor cell apoptosis, accelerate the release of drugs, and increase the sensitivity of tumor cells to chemotherapy, thus increasing treatment effect. At the same time, the detached GQDs can take advantage of their extremely small size (5–10 nm) to penetrate deeply into tumor tissues, solving the problem of low permeability of traditional nanoparticles. By utilizing the photothermal properties of GQDs, synergistic photothermal conversion between GQDs and MCN was realized for the purpose of synergistic photothermal treatment of superficial and deep tumor tissues. Full article

This study demonstrated the capability of two readily available optical spectroscopy tools, namely UV-Vis absorption spectrophotometry and Raman/surface-enhanced Raman spectroscopy, to select in a rapid and noninvasive manner the most homogenous gold nanoparticle (AuNP) models and to identify their chemical binding mechanism to 2-thiouracil (2-TU). 2-TU is an anticancer drug of great promise in the antiproliferative and photothermal therapies of cancer. The citrate-capped AuNPs emerged as the most stable as well as time- and cost-effective AuNP model out of the three widely used colloidal nanocores (citrate-, borohydride-citrate-, and sodium dodecyl sulfate (SDS)-capped AuNPs) that were examined. 2-TU chemically attached to the relatively monodispersed AuNPs via a chemisorption mechanism. The 2-TU-AuNPs complex formed through the covalent bonding of the S atom of 2-TU to the nanosurface in a vertical orientation. The spectroscopic results were then confirmed with the help of density functional theory (DFT) calculations and other physicochemical characterization tools for nanomaterials such as transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential. Overall, the purified 2-TU-AuNPs were found to be spherical, had an average diameter of 25 ± 2 nm, a narrow size distribution (1–30 nm), a sharp localized surface plasmon resonance (LSPR) peak at 525 nm, and a negative surface charge (−14 mV). Full article

Microplastics (MPs) are emerging pollutants and pose a significant threat to marine ecosystems. Although previous studies have documented the mechanisms and toxic effects of aging MPs in various environments, the impact of the marine environment on MPs remains unclear. In the present study, the aging process of polystyrene (PS) in seawater was simulated and the changes in its physicochemical properties were investigated. Our results showed that the surface of the PS eroded in the seawater, which was accompanied by the release of aged MPs with a smaller size. In situ optical photothermal infrared microspectroscopy revealed that the mechanism of PS aging was related to the opening of the carbonyl group and breaking of the bond between carbon and benzene removal. To verify the toxic effects of aged PS, Caenorhabditis elegans was exposed to PS. Aged PS resulted in a greater reduction in locomotion, vitality, and reproduction than virgin PS. Mechanistically, aged PS led to oxidative stress, high glutathione s-transferase activity, and high total glutathione in worms. Together, our findings provided novel information regarding the accelerated aging of PS in seawater and the increased toxicity of aged PS, which could improve our understanding of MPs’ ecotoxicity in the marine environment. Full article

Quercetin (QCT) is a promising dose-dependent nutraceutical that usually suffers from poor water solubility and low bioavailability issues. In this work, a novel QCT-loaded nanoscale delivery system was constructed based on the oxidative self-polymerization of melanin (Q@MNPs). The FT-IR, XRD, and Zeta potential analyses confirmed that QCT was successfully absorbed on the melanin nanoparticles (MNPs) via Π−Π and hydrogen bonding interactions. The encapsulation efficiency and particle size of Q@MNPs were 43.78% and 26.68 nm, respectively. Q@MNPs improved the thermal stability of QCT and the antioxidant properties in comparison to MNPs. Meanwhile, Q@MNPs presented fantastic photothermal conversion capacity and stability triggered by the NIR laser, which significantly enhanced the antibacterial capability with a sterilization rate of more than 98% against E. coli and S. aureus. More importantly, Q@MNPs exhibited NIR/pH dual-responsive drug release behavior and good biocompatibility (at concentrations of < 100 μg/mL). Thus, Q@MNPs show promising prospects for flavonoid delivery. Full article

The pursuit of efficient, profitable, and ecofriendly materials has defined solar cell research from its inception to today. Some materials, such as copper nitride (Cu₃N), show great promise for promoting sustainable solar technologies. This study employed reactive radio-frequency magnetron sputtering using a pure nitrogen environment to fabricate quality Cu₃N thin films to evaluate how both temperature and gas working pressure affect their solar absorption capabilities. Several characterization techniques, including X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS), Raman spectroscopy, scanning electron microscopy (SEM), nanoindentation, and photothermal deflection spectroscopy (PDS), were used to determine the main properties of the thin films. The results indicated that, at room temperature, it is possible to obtain a material that is close to stoichiometric Cu₃N material (Cu/N ratio ≈ 3) with (100) preferred orientation, which was lost as the substrate temperature increases, demonstrating a clear influence of this parameter on the film structure attributed to nitrogen re-emission at higher temperatures. Raman microscopy confirmed the formation of Cu-N bonds within the 628–637 cm⁻¹ range. In addition, the temperature and the working pressure significantly also influence the film hardness and the grain size, affecting the elastic modulus. Finally, the optical properties revealed suitable properties at lower temperatures, including bandgap values, refractive index, and Urbach energy. These findings underscore the potential of Cu₃N thin films in solar energy due to their advantageous properties and resilience against defects. This research paves the way for future advancements in efficient and sustainable solar technologies. Full article