High Photothermal Conversion Efficiency Research Articles

Isoindigo-Based Dual-Acceptor Conjugated Polymers Incorporated Conjugation Length and Intramolecular Charge Transfer for High-Efficient Photothermal Conversion.

Photothermal tumor therapy (PTT) and photoacoustic imaging (PA) have emerged as promising noninvasive diagnostic and therapeutic approaches for cancer treatment. However, the development of efficient PTT agents with high photostability and strong near-infrared (NIR) absorption remains challenging. This study synthesizes three isoindigo-based dual-acceptor conjugated polymers (CPs) (P-IIG-TPD, P-IIG-DPP, and P-IIG-EDOT-BT) via a green and nontoxic direct arylation polymerization (DArP) method and characterizes their optical, electrochemical, and NIR photothermal conversion properties. By incorporating two acceptors into the backbone, the resulting polymers exhibit enhanced photothermal conversion efficiency (PCE) due to improved synergy among conjugation length, planarity, and intramolecular charge transfer (ICT). The nanoparticles (NPs) of P-IIG-EDOT-BT and P-IIG-DPP have a uniform size distribution around 140nm and exhibit remarkable NIR absorption at 808nm. In addition, P-IIG-EDOT-BT and P-IIG-DPP NPs exhibit high PCEs of 62% and 78%, respectively. This study promotes the molecular design of CPs as NIR photothermal conversion materials and provides guidance for the development of novel dual-acceptor CPs for tumor diagnosis and treatment.

Rapid Light Response of a Novel Bi‐Based Metal–Organic Framework for Bacterial Wound Infections Treatment

AbstractBismuth metal–organic frameworks (MOFs) as catalysts are scarce. Herein, the first MOF comprising meso‐ tetra(4‐carboxyphenyl) porphine (TCPP) as an organic ligand and Bi ion as a metal node, denoted as Bi‐TCPP, is synthesized by a convenient one‐step hydrothermal method. Compared to other 2D (Cu‐TCPP) or 3D (PCN‐222) MOFs with TCPP as a ligand, Bi‐TCPP has ultrafast singlet oxygen generation ability and a high photothermal conversion efficiency of 49.5% under the irradiation of 660 nm light. This is due to Bi‐TCPP's strong ligand‐to‐metal charge transfer (LMCT) events that form singlet oxygen (1O2). Further, when the electrons and holes above the bandgap relax to the band edge, the excess energy is converted into heat. In vitro and in vivo experiments show excellent antibacterial and repair effects. Hence, the synthesis of Bi‐TCPP provides new ideas for the study of rare bismuth‐based MOFs, and its excellent biocompatibility provides a possibility for further application.

Selenadiazolesbenzothiadiazole‐Based Small Donor–Acceptor–Donor Dye for Photothermal Therapy in NIR‐II Window

AbstractRecently, photothermal therapy (PTT) has attracted enormous attention because of its low invasiveness, high spatiotemporal selectivity, and good therapeutic effect. Different types of photothermal conversion agents have been developed, particularly the second near‐infrared window (NIR‐II, 1000–1700 nm) organic small molecular dyes which have become an attractive research direction. Herein, a novel and simple donor–acceptor–donor (D–A–D) type NIR‐II dye SeC is designed and synthesized with 2λ4δ2‐[1,2,5]selenadiazolo[3,4‐f]‐2,1,3‐benzothiadiazole structure. To improve capability of SeC for biomedical applications, SeC molecules are encapsulated into DSPE‐PEG2000 to construct nanoparticles SeC‐NPs, which show high photostability and biocompatibility. More importantly, SeC‐NPs exhibited an excellent photothermal performance and display high photothermal conversion efficiency (PCE) of 62% under 808 nm excitation. Because of favorable fluorescence property in NIR‐II window and high PCE, SeC‐NPs are successfully used for NIR‐II imaging and PTT of 4T1 tumor‐bearing mice models. In vivo studies demonstrate SeC‐NPs’ ability to suppress tumor growth under NIR photoirradiation without visible damage to main organs. Overall, this study develops a strategy to design a simple small molecule dye containing selenium for NIR‐II imaging, and SeC‐NPs shows high performance for PTT toward tumor.

Polydopamine-coated ferric oxide nanoparticles for R848 delivery for photothermal immunotherapy in breast cancer

Breast cancer, which requires comprehensive multifunctional treatment strategies, is a major threat to the health of women. To develop multifunctional treatment strategies, we combined photothermal therapy (PTT) with immunotherapy in multifunctional nanoparticles for enhancing the anti-tumor efficacy. Fe3O4 nanoparticles coated with the polydopamine shell modified with polyethylene glycol and cyclic arginine-glycyl-aspartic peptide/anisamide (tNP) for loading the immune adjuvant resiquimod (R848) (R848@tNP) were developed in this research. R848@tNP had a round-like morphology with a mean diameter of 174.7 ± 3.8 nm, the zeta potential of −20.9 ± 0.9 mV, the drug loading rate of 9.2 ± 1.1 %, the encapsulation efficiency of 81.7 ± 3.2 %, high photothermal conversion efficiency and excellent magnetic properties in vitro. Furthermore, this research also explored the anticancer efficacy of nanoparticles against the breast cancer under the near-infrared (NIR) light (808 nm) in vitro and in vivo. R848@tNP-based NIR therapy effectively inhibited the proliferation of breast cancer cells. Moreover, R848@tNP mediated PTT significantly enhanced the maturation of dendritic cells in vitro. Additionally, R848@tNP enhances the anti-tumor effect and evoked an immune response under NIR in vivo. Furthermore, the biosafety of R848@tNP was fully investigated in this study. Collectively, these results clearly demonstrate that R848@tNP, with magnetic resonance imaging characteristics, is a potential therapeutic for breast cancer that combines PTT with the immunotherapy.

Enhanced photothermal conversion performance of MWCNT/SiC hybrid aqueous nanofluids in direct absorption solar collectors

Nanofluids containing light-absorbing nanoparticles are potential alternative working fluids in solar collectors. In this work, a novel hybrid aqueous nanofluid containing multi-walled carbon nanotubes (MWCNTs) and SiC nanoparticles is prepared to improve the photothermal conversion ability of working fluids. The hybrid nanofluid overcomes the disadvantages of one-component nanofluids and achieves good solar absorption on the merit of the complementary optical property of MWCNTs and SiC nanoparticles. The prepared nanofluids show excellent stability due to the hydroxyl functionalization of MWCNTs, and the thermal conductivity of hybrid nanofluids is also enhanced. A high photothermal conversion efficiency of 64.7 % is achieved by the hybrid nanofluid after 1-hour irradiation, which is significantly higher than that of the reported MWCNT-based aqueous nanofluids in the literature. Meanwhile, the mechanism of efficiency enhancement in MWCNT/SiC hybrid nanofluids is analyzed. This study promotes the application of MWCNT/SiC hybrid nanofluids as light-absorbing working fluids in solar collectors.

PH-Activated Ce-Doped Molybdenum Oxide Nanoclusters for Tumor Microenvironment Responsive Photothermal and Chemodynamic Therapy.

Molybdenum-based nanomaterials have shown promise for anticancer treatment due to their strong photothermal and redox-activated capabilities. Herein, we have fabricated cerium-doped MoOx (Ce-MoOv) with tunable Mo/Ce molar ratios by a one-pot method and investigated their effect on chemodynamic therapy (CDT) and photothermal therapy (PTT). It is found that Ce-MoOv can self-assemble into nanoclusters in acidic conditions and the increasing Ce amount will generate oxygen vacancy defects and induce the valence change of Mo6+/Mo5+ and Ce4+/Ce3+, which leads to strong near-infrared absorption with high photothermal conversion efficiency of 71.31 and 49.86% for 808 and 1064 nm. Other than photothermal conversion, the materials demonstrate pH-/glutathione (GSH)-activated photoacoustic (PA) imaging capability in vitro. In addition, Ce-MoOv acts as a CDT reagent capable of converting endogenous H2O2 to two types of reactive oxygen species (•OH, 1O2) while depleting GSH. Ce-MoOv demonstrates an excellent therapeutic effect against HCT116 cells and effectively reduces the intracellular GSH level and significantly increases the number of reactive radicals under 1064 nm laser irradiation as compared with the no-laser group in vitro. This work provides a new paradigm using lanthanide-doped polymetallic oxides for pH-/GSH-responsive photothermal/chemodynamic therapy with PA imaging ability.

Synthesis and characterization of wood-based phase change material with high photothermal conversion efficiency

Abstract Phase change materials attract tremendous interest for building energy conservation due to their auto-temperature regulation and thermal energy storage capacity. However, its practical application is hindered due to the leakage problem and poor photothermal conversion efficiency. To address these issues, a scalable wood-based phase change material was prepared by impregnating polyethylene glycol (PEG) into wood particles doped with Fe3O4 and subsequent a hot press in this study. PEG was encapsulated by wood particles through its abundant pore structure and leakage rate of prepared wood-based phase change material (FWPCM) was only 2.9%, which solved the leakage problem effectively. FWPCM presented high latent heat of 73 J g−1 and slowed down the temperature change obviously. Addition of Fe3O4 powder endowed FWPCM a high photothermal conversion efficiency and thermal conductivity (0.3545 W/(m*K) was increased by 125% compared to PW. So FWPCM had potential to be used as building engineering material for energy collecting, storage and conversion benefited by its great thermal performance, superior durability, simple preparing process and acceptable mechanical property.

Development and characterization of pH-responsive nanocarriers for chemo-photothermal combination therapy of acidic tumors.

The combination of photothermal therapy and chemotherapy has been considered a promising strategy for improving the excellent antitumor activities of these treatments. In this study, we developed a new simple type of pH-sensitive chemo-photothermal combination agent capable of repeated exposures to a near-infrared (NIR) laser and evaluated its anticancer efficacy in vitro and in vivo. Doxorubicin (Dox) and gold nanoclusters (GNCs) were successfully co-loaded into pH-sensitive nanoparticles (poly(ethylene glycol)-poly[(benzyl-l-aspartate)-co-(N-(3-aminopropyl)imidazole-L-aspartamide)] (PEG-PABI)), resulting in a particle size of approximately120 nm with a narrow size distribution. The dual drug-loaded nanoparticles (Dox/GNC-loaded PEG-PABI micelles (Dox/GNC-Ms)) showed consistent pH-sensitive properties and heat generation efficiency after repeated NIR laser exposure. In particular, GNC-M has improved photothermal stability while maintaining high photothermal conversion efficiency, addressing the shortcomings of previous gold nanoparticles. As the concentration of GNC-Ms, irradiation light exposure time, and light source intensity increased, the amount of heat generated and the anticancer effect increased. When Dox was encapsulated with GNCs (Dox/GNC-Ms), a faster drug release rate under acidic pH conditions and a strong synergistic effect against U87MG cells were observed. When the Dox/GNC-M system was extended to in vivo studies, it effectively increased the temperature of the tumor tissue under near-infrared irradiation and showed excellent anticancer efficacy. Therefore, the Dox/GNC-M system could be a simple but promising strategy for chemo-photothermal combination treatment capable of targeting acidic tumors.

An adjustable transpiration polyimide membrane for highly efficient personal drying and warming

Functional textiles with efficient sweat releasing and thermal insulating play a pivotal role in maintaining physiological comfort in cold winter. However, the breathability and warmth have conflicting structural demands on the conventional fabric. Here, a porous polyimide film (PIF) with tunable sweat release capability was prepared by growing a graphene layer through laser-ablation strategy. Jungle-like graphene layer offers the porous PI film with distinct advantages, including a desired super hydrophobic performance (water contact angle =153°), rapid air permeability (1572 g/m2·24 h), quick drying function based on high photo-thermal and electro-thermal conversion efficiency, and outstanding thermal insulating capability (0.033 W/m·K). Moreover, the graphene layer can also be custom printed into various patterns, which expanded the application scenarios for wearable flexible electronics. Overall, this Janus design offered insight into the proactive control of sweat release and heat transfer within the hierarchical and interconnected network, providing promising benefits to the development of multifunctional drying and warming textiles.

Dual-Driven Functional Fabric with High Electrothermal and Photothermal Conversion Efficiency Modified by CuS Nanoparticles

As an ideal substrate for active material integration, fabrics of nanofiber bundles have held great promise due to their outstanding surface area, unique mechanical flexibility, and textile structure. Herein, a polyethylene nanofiber bundle (PNB) fabric was prepared via melt blending extrusion followed by chemical deposition of a copper sulfide (CuS) active layer. Benefiting from the high conductivity and the outstanding light absorption characteristics of CuS, CuS/PNB fabrics exhibited excellent photo and electric dual-driven energy conversion performance. Specifically, the CuS/PNB fabrics showed the highest electrical conductivity (277 S m–1), exceptional Joule heating (up to 85.7 °C at a voltage of 0.8 V), a low working voltage (0.2–0.8 V), and long-term stability. Furthermore, the photo-absorption efficiency and surface temperature reached 94.3% and 91.2 °C under the irradiation of 1 sun, respectively. Meanwhile, the CuS/PNB fabrics exhibited a high specific evaporation rate of up to 1.81 kg m–2 h–1, as well as an energy conversion efficiency of 95.1% under one solar irradiation. We believe that such a functional fabric offers a strategy for energy harvesting and conversion fields and displays promising applications in warmth-keeping and solar-driven water evaporation in the future.

Multifunctional Actuator Based on Graphene/PDMS Composite Materials with Shape Programmable Configuration and High Photothermal Conversion Capability.

Photoresponsive smart actuators based on carbon materials are attracting increasing attention. However, the low content of carbon materials currently limits the development of carbon material actuators. In this work, we designed and prepared a multifunctional bilayer composite actuator with controllable structures and high photothermal conversion efficiency. The actuator consists of a graphene/polydimethylsiloxane (PDMS) composite layer and a PDMS layer. With an ultrahigh graphene mass fraction (30%), the actuator exhibits a good hydrophobicity, unexpectedly high photothermal conversion performance (from room temperature to 120 °C within 1 s), and rapid photo-response capability. By thermal regulation, ultraviolet laser cutting, and assembly, the actuator can achieve shape programmable configuration in three-dimensional directions. Bionic crawling robots achieve a crawling speed of 0.065 mm/s, and liquid tracking robots achieve a rotational motion of 106°/s, a linear motion of 8.42 mm/s, and a complex "W"-shaped trajectory motion. This work provides a simple and effective method for the preparation and realization of multifunctional actuators based on graphene composite materials.

Oxygen vacancy engineering of TiO2 nanosheets for enhanced photothermal therapy against cervical cancer in the second near-infrared window

Cervical cancer is the most common and deadly female cancer on the worldwide scale. Considering that the conventional surgery treatment and chemotherapy would cause certain side effects, photothermal therapy (PTT) possesses desired therapeutic efficiency and insignificant side effects against cervical cancer. However, the lack of efficient and safe photothermal agents that operate in the second near-infrared (NIR-II) window is a main obstacle hindering the clinical transformation of PTT. Titanium dioxide (TiO2)-based nanomaterials are commonly applied in the biomedicine field, but the weak absorption and low photothermal conversion efficiency (PCE) of TiO2 in the NIR region limit their applications in PTT. Herein, we report the oxygen vacancy engineering that is a robust strategy to regulate the electronic structures of TiO2 for photothermal conversion properties optimizing. The obtained oxygen vacancy-doped TiO2−x nanosheets exhibit strong NIR-II absorption and high PCE owing to their decreased bandgap. Specifically, the PCE of TiO2−x nanosheets is determined to be 69.5 % in the efficient NIR-II window, which is much higher than that of widely reported PTT agents. Complete tumor recession without recurrence or pulmonary metastasis is realized by enhanced NIR-II PTT via TiO2−x nanosheets at an ultralow and safe laser exposure (0.6 W/cm2). Our findings suggest that oxygen vacancy engineering of nanomaterials could regulate their photothermal conversion performances, promoting the further application of TiO2-based nanomaterials in the biomedical.

4D direct laser writing of photo-triggered liquid crystal elastomer microactuators with large actuation strain

4D printed photo-triggered liquid crystal elastomers (LCEs) microactuators by direct laser writing via two-photon polymerization (DLW-TPP) have attracted increasing attention due to their manipulation flexibility, reversible and rapid actuation capabilities. However, their development is hampered by the lack of room-temperature printable liquid crystal (LC) photoresists. Here, we developed new light-responsive LC photoresists by incorporating novel conjugated polymers (CPs) as photothermal agents for the DLW-TPP technology. The CPs displayed a remarkable photothermal effect and effectively avoided the aggregation problems that always happened for inorganic nanoparticles in photoresists. Moreover, the CPs incorporation lowered the nematic-to-isotropic temperature of the LC photoresists which is beneficial for room-temperature DLW-TPP. The printing parameters, including laser power and scanning speed, were investigated using the developed LC photoresists. It was found the range of printing parameters decreased with the increase of the CPs loading fraction from 0.1 to 0.5 wt%, which was attributed to the high photothermal conversion efficiency (52.7%). A well-defined CPs/LCEs microactuator with CPs as low as 0.3 wt% was printed, which could achieve a large 25.0% actuation strain in 5 s upon near-infrared (NIR) light stimulation. It could be used for thriving soft micro-robotics and micro-membranes with controllable separation capabilities.

Pd decorated MoS2 nanoflowers as photothermal catalyst for enhanced NIR-induced 4-nitrophenol reduction

Photothermal catalysis has aroused increasing interests due to its huge potential in environmental purification, and the key is to develop efficient photothermal catalytic materials. In this work, 4-nitrophenol (4-NP) is chosen as the probe molecule of nitroaromatics. A Pd/MoS2 catalyst prepared by two-step hydrothermal method has been identified as a highly active and stable catalyst in the photothermal catalytic reduction of 4-NP. Besides, Pd/MoS2 nanoflowers have wide-range photo-absorption between 200 and 1100 nm and high photothermal conversion efficiency of 43 %. Under the irradiation of 808 nm laser, Pd/MoS2 nanoflowers showed a 6-fold reduction rate for 4-NP compared to MoS2 nanoflowers. Intriguingly, Pd/MoS2 catalyst exhibited higher activities under photothermal heating than that under oil bath heating with the same reaction temperature. Additionally, the Pd/MoS2 nanoflowers could show high and stable 4-NP reduction rate with slight morphology change after 7 cycling reaction tests, implying excellent recyclability. These results demonstrate that Pd/MoS2 nanoflowers and photothermal catalysis offer new opportunities for the catalytic elimination of organic pollutants from water.

3D-printed tripodal porous wood-mimetic cellulosic composite evaporator for salt-free water desalination

Solar desalination based on interfacial evaporation has been proven promising in producing clean water. However, so far, the lack of a facile preparation strategy and effective salt rejection has profoundly limited its potential for practical applications. Herein, inspired by the unique liquid transportation of natural wood, we report on a three-dimensional (3D) printed tripodal porous wood-mimetic cellulosic composite evaporator for long-term salt rejection, starting from cost-effective materials such as cellulose and carbon black. The printed evaporator displays a broadband solar absorption (>97%) and an extremely low thermal conductivity (0.075 W m−1 K−1), indicating its high photothermal conversion efficiency and outstanding thermal management. The printed tripodal porous evaporator contains large-sized channels (∼1 mm in diameter) that function as salt regenerating pathways, micropores (∼30 μm) and submicron pores (∼1 μm) for rapid water transport and efficient supply. Fluidic simulation reveals that large channels with high water flux lead to the salt concentration gradient between large and small channels via submicropores, meanwhile, the concentrated water at the top layer transports downward by diffusion and convection, further making the spontaneous horizontal and vertical salt exchange. Such a tripodal porous structure endows the evaporator with a high efficiency of ∼75% in a highly concentrated salt solution (15 wt% NaCl) under 1 sun irradiation, as well as superior salt-rejection property (100 h continuous evaporation in 15 wt% NaCl). This strategy, starting with sustainable cellulose-based composite materials and being able to balance the evaporation performance and long-term stability, opens up new doors toward clean water production.

Quinoxalineimide-Based Semiconducting Polymer Nanoparticles as an Effective Phototheranostic for the Second Near-Infrared Fluorescence Imaging and Photothermal Therapy.

Multifunctional theranostics play a critical role in improving the efficacy of photothermal therapy and tumor fluorescence imaging; however, they require the integration of complex components into a single theranostic system, and their response in the second near-infrared (NIR-II) region is constrained by wavelengths of a photosensitizer. To address this issue, we herein developed a novel multifunctional thiazole-fused quinoxalineimide semiconducting polymer (named PQIA-BDTT), which exhibits NIR-II fluorescence and photothermal properties. PQIA-BDTT nanoparticles achieved an impressively high photothermal conversion efficiency (72.6%) in laser (1064 nm)-induced photothermal therapy at a safe maximum permissible exposure, demonstrating their capability as an effective photothermal agent. Moreover, PQIA-BDTT nanoparticles can be used as a reference for NIR-II fluorescence imaging under a low laser fluence. The tumor size and location in 4T1 mice intravenously injected with the PQIA-BDTT nanoparticles could be precisely identified through NIR-II fluorescence imaging, which also exhibited remarkable photothermal antitumor efficacy by in vitro and in vivo therapy. Overall, this study demonstrates that introducing a thiazole-fused quinoxalineimide acceptor unit into a donor-acceptor conjugated polymer is an effective strategy for the synthesis of novel multifunctional theranostic systems, which provides a novel platform for designing theranostic agents for biomedical applications.

Defect Rich MoSe2 2H/1T Hybrid Nanoparticles Prepared from Femtosecond Laser Ablation in Liquid and Their Enhanced Photothermal Conversion Efficiencies.

MoSe2 2H/1T hybrid nanoparticles are prepared by femtosecond laser ablation of MoSe2 powder in isopropyl alcohol with different laser powers and ablation times, and their formation mechanisms and photothermal conversion efficiencies (PTCEs) are studied. Two types of spherical nanoparticles are observed. The first type are onion-structured nanoparticles that are formed by nucleation on the surfaces of melted droplets followed by inward growth of {002} planes of MoSe2 . The second type are polycrystalline nanoparticles, formed by coalescence of crystalline nanoclusters fragmented from the powder during the laser ablation. The nanoparticle size in all samples shows a bimodal distribution, corresponding to different fragmentation mechanisms. The 2H-to-1T phase transition in the nanoparticles is likely caused by electron doping from the laser-induced plasma. The PTCEs of the nanoparticles increase with laser power and ablation time, the highest PTCE is around 38%. After examining the bandgaps and the Urbach energies of the nanoparticles, it is found that the high PTCEs are primarily attributed to defects and structural disorder in the laser-synthesized nanoparticles, which allow absorption of photons with energies smaller than the bandgap energy and facilitate non-radiative recombination of photo-excited carriers. This article is protected by copyright. All rights reserved.

Cellulose-based phase change membranes with reversible optical transmittance and lignin ester-enhancing photothermal conversion performance

Leakage issues and low photothermal conversion efficiencies have limited the application of organic solid–liquid phase-change materials. Herein, cellulose-based phase-change membranes (CPCM-FAS-LUEX) were prepared by physically blending three fatty alcohols (1-dodecanol, 1-tetradecanol, and 1-hexadecanol) with a cross-linked network composed of cellulose 10-undecenoyl ester (CUE), lignin 10-undecenoyl ester (LUE), and octadecyl acrylate (OA) with 2,2′-azobis(2-methylpropionitrile) as an initiator. In addition to being part of the network structure, LUE acted as a photothermal conversion enhancer. During phase change processes, the prepared membranes exhibited reversible optical transmittance, the response temperature of which could be adjusted (21–49 °C) by using different fatty alcohols. Differential scanning calorimetry revealed that the CPCM-FAS-LUEX membranes possessed good thermal energy storage capacities, with melting enthalpies up to 134.9 J/g. The introduction of LUE significantly improved the photothermal conversion performance, with an increase in efficiency from 42.06% to 88.66% at a light intensity of 230 mW/cm2. It is noteworthy that reversible optical transmittance and high photothermal conversion efficiency were achieved in the same materials. Hence, the synthesized CPCM-FAS-LUEX membranes have potential for use in thermal–response materials and solar–thermal storage and conversion systems.

DNA-Templated Ag@Pd Nanoclusters for NIR-II Photoacoustic Imaging-Guided Photothermal-Augmented Nanocatalytic Therapy.

Developing multifunctional nanozymes with photothermal-augmented enzyme-like reaction dynamics in the second near-infrared (NIR-II) biowindow is of significance for nanocatalytic therapy (NCT). Herein, DNA-templated Ag@Pd alloy nanoclusters (DNA-Ag@Pd NCs) are prepared as a kind of novel noble-metal alloy nanozymes by using cytosine-rich hairpin-shaped DNA structures as growth templates. DNA-Ag@Pd NCs exhibit high photothermal conversion efficiency (59.32%) under 1270nm laser and photothermally augmented peroxidase-mimicking activity with synergetic enhancement between Ag and Pd. In addition, hairpin-shaped DNA structures on the surface of DNA-Ag@Pd NCs endow them with good stability and biocompatibility in vitro and in vivo, and enhanced permeability and retention effect at tumor sites. Upon intravenous injection, DNA-Ag@Pd NCs demonstrate high-contrast NIR-II photoacoustic imaging-guided efficient photothermal-augmented NCT of gastric cancer. This work provides a strategy to synthesize versatile noble-metal alloy nanozymes in a bioinspired way for highly efficient therapy of tumors.

One step synthesis of novel CuS-ZnS/SiO2@n-octadecane nanocapsules with full spectral absorption range and high photothermal conversion efficiency

In this manuscript, CuS-ZnS/SiO2@n-octadecane nanocapsules were prepared by a simple one-step Cu2+ and Zn2+ co-deposition method. The results of XRD, SEM, TEM, FTIR and XPS show that nanocapsules composed of CuS-ZnS/SiO2 shell and n-octadecane core material were successfully prepared, and the particles deposited was proved to be composite structure of CuS-ZnS. The solution concentration, reaction temperature and pH value have significant effects on the morphology of the nanocapsules prepared. The appropriate conditions are 0.02 mol/L CuSO4, 0.02 mol/L Zn(CH3COO)2, 60 °C, and no additional pH adjustment. Under the optimum conditions, the melting enthalpy reached 45.11 J/g, and after 100 times of cold and hot cycles, the melting enthalpy of the sample only decreased by 3.2%, showing good thermal stability. The CuS-ZnS composite structure makes CuS-ZnS/SiO2 nanocapsules exhibit a wider spectrum absorption performance. The absorption effect of CuS-ZnS/SiO2 nanocapsules to ultraviolet light is significant, compared to the slight reducing of the visible light, while the absorption of near-infrared light is strong. The photothermal conversion efficiency of the samples is significantly improved from 9.7% to 86.6%. Hence, the prepared nanocapsules achieve full spectral absorption, which has a broad application prospect in solar thermal utilization.