Excellent Photothermal Properties Research Articles

MoS2 quantum dots based on lipid drug delivery system for combined therapy against Alzheimer's disease

Pathological pathways of Alzheimer's disease (AD) are criss-crossed, various pathological factors are dynamically correlated and relatively independent, which makes the single-target drug therapy less effective. Therefore, rational use of multiple therapeutic strategies for accurate inhibition of multiple pathological targets are effective to enhance the efficacy of AD therapy. The combination of drug loading and the excellent photothermal conversion property of nanocomposites is highly innovative to combat the two prominent pathological factors of Alzheimer's disease, oxidative stress and amyloid-β-(1–42) (Aβ1-42) deposition caused by reactive oxygen species (ROS) imbalance. Molybdenum disulfide quantum dots (MoS2 QDs) were selected as carriers and functionalized with lipids (MoS2 QDs/lipid) to improve their dispersibility in water, while effectively escaping immune clearance, improving the efficiency of multi-target applications and targeting advantages. The loading of curcumin (MoS2 QDs/lipid-Cur) not only overcomes the disadvantages of poor water solubility and low bioavailability of the drug, but also achieves the function of sustained release and long-term effect. MoS2 QDs/lipid-Cur showed excellent performance in the two therapeutic targets of anti-Aβ1-42 deposition and elimination of ROS in the early stage, and also obtained consistent excellent results in cell experiments. The drug-loaded combined with NIR treatment group significantly reduced Aβ1-42 mediated neurotoxicity. The in vivo photothermal experiment showed that NIR irradiation in the mouse brain can effectively open the blood-brain barrier (BBB) and increase the permeability of the material to the BBB. At the same time, NIR irradiation enriched drug-loaded material in the mouse brain, resulting in a significant increase in the temperature difference between the mice brains. MoS2 QDs/lipid-Cur is an excellent nanocomposite that integrates multiple functions and can be used for multi-target therapy.

Au@MOFs used as peroxidase-like catalytic nanozyme for bacterial infected wound healing through bacterial membranes disruption and protein leakage promotion

Bacterial biofilms often hinder the healing of infected chronic wounds. Hence, it is significant to explore ways to destroy bacterial biofilms. In this work, a photothermal therapy strategy of designing Au clusters modified ZIF-8 MOFs (Au@ZIF-8) as peroxidase-like catalytic nanozyme was proposed for bacterial infected wound healing. Under near-infrared laser (NIR), the prepared Au@ZIF-8 present enhanced peroxidase-like activity and excellent photothermal response properties. Au@ZIF-8 achieved bacterial membrane disruption rate of 66.3% and MRSA clearance rate up to 97%. Au@ZIF-8 also catalyzed endogenous H2O2 to OH and achieved almost 97.4% healing rate in animal experiments. The prepared Au@ZIF-8 with peroxidase-like catalytic nanozyme properties has great potential in the treatment of infected diabetic wounds through bacterial membranes disruption and protein leakage promotion.

An All-in-One "4A Hydrogel": through First-Aid Hemostatic, Antibacterial, Antioxidant, and Angiogenic to Promoting Infected Wound Healing.

Currently used wound dressings are ineffective. Hence, there is a need to develop introduce a high-performance medicament with multiple functions including rapid hemostasis and excellent antibacterial activity to meet the growing worldwide demand for wound healing products. Here, inspired by the strong adhesion of mussels and the enzyme-mimicking activity of nanometallic biomaterials, the authors developed an injectable hydrogel to overcome multiple limitations of current wound dressings. The hydrogel is synthesized via esterification reaction between poly(vinyl alcohol) (PVA) and 3,4-dihydroxyphenylalanine (DOPA), followed by catechol-metal coordination between Cu2+ and the catechol groups of DOPA to form a PVA-DOPA-Cu (PDPC) hydrogel. The PDPC hydrogel possesses excellent tissue adhesive, antioxidative, photothermal, antibacterial, and hemostatic properties. The hydrogel rapidly and efficiently stopped bleeding under different traumatic conditions, including otherwise-lethal liver injury, high-pressure carotid artery rupture, and even fatal cardiac penetration injuries in animal models. Furthermore, it is demonstrated that the PDPC hydrogel affected high-performance wound repair and tissue regeneration by accelerating re-epithelialization, promoting collagen deposition, regulating inflammation, and contributing to vascularization. The results show that PDPC hydrogel is a promising candidate for rapid hemorrhage control and efficient wound healing in multiple clinical applications.

Efficient Fabrication of Micro/Nanostructured Polyethylene/Carbon Nanotubes Foam with Robust Superhydrophobicity, Excellent Photothermality, and Sufficient Adaptability for All-Weather Freshwater Harvesting.

The integration of fog collection and solar-driven evaporation has great significance in addressing the challenge of the global freshwater crisis. Herein, a micro/nanostructured polyethylene/carbon nanotubes foam with interconnected open-cell structure (MN-PCG) is fabricated using an industrialized micro extrusion compression molding technology. The 3D surface micro/nanostructure provides sufficient nucleation points for tiny water droplets to harvest moisture from humid air and a fog harvesting efficiency of 1451mg cm-2 h-1 is achieved at night. The homogeneously dispersed carbon nanotubes and the graphite oxide@carbon nanotubes coating endow the MN-PCG foam with excellent photothermal properties. Benefitting from the excellent photothermal property and sufficient steam escape channels, the MN-PCG foam attains a superior evaporation rate of 2.42kg m-2 h-1 under 1 Sun illumination. Consequently, a daily yield of ≈35kg m-2 is realized by the integration of fog collection and solar-driven evaporation. Moreover, the robust superhydrophobicity, acid/alkali tolerance, thermal resistance, and passive/active de-icing properties provide a guarantee for the long-term work of the MN-PCG foam during practical outdoor applications. The large-scale fabrication method for an all-weather freshwater harvester offers an excellent solution to address the global water scarcity.

Combining Upconversion Luminescence, Photothermy, and Electrochemistry for Highly Accurate Triple-Signal Detection of Hydrogen Sulfide by Optically Trapping Single Microbeads.

The detection of hydrogen sulfide (H2S), the third gas signaling molecule, is a promising strategy for identifying the occurrence of certain diseases. However, the conventional single- or dual-signal detection can introduce false-positive or false-negative results, which ultimately decreases the diagnostic accuracy. To address this limitation, we developed a luminescent, photothermal, and electrochemical triple-signal detection platform by optically trapping the synthetic highly doped upconversion coupled SiO2 microbeads coated with metal-organic frameworks H-UCNP-SiO2@HKUST-1 (H-USH) to detect the concentration of H2S. The H-USH was first synthesized and proved to have stable structure and excellent luminescent, photothermal, and electrochemical properties. Under 980 nm optical trapping and 808 nm irradiation, H-USH showed great detection linearity, a low limit of detection, and high specificity for H2S quantification via triple-signal detection. Moreover, H-USH was captured by optical tweezers to realize quantitative detection of H2S content in serum of acute pancreatitis and spontaneously hypertensive rats. Finally, by analyzing the receiver operating characteristic (ROC) curve, we concluded that triple-signal detection of H2S was more accurate than single- or dual-signal detection, which overcame the problem of false-negative/positive results in the detection of H2S in actual serum samples.

Magnetic iron oxide nanoparticle-loaded hydrogels for photothermal therapy of cancer cells.

Introduction: Non-invasive photothermal therapy (PTT) is a competitive treatment for solid tumors, while the efficacy is largely dependent on the effective retention of photothermal converters in tumor tissues. Methods: Herein, the development of iron oxide (Fe3O4) nanoparticle-loaded alginate (ALG) hydrogel platform for PTT of colorectal cancer cells is reported. Fe3O4 nanoparticles synthesized via coprecipitation method after reaction of 30 min have a small size (61.3 nm) and more suitable surface potential, and can mediate PTT under near-infrared (NIR) laser irradiation. The premix of Fe3O4 nanoparticles and ALG hydrogel precursors can be gelatinized by Ca2+-mediated cross-linking to form this therapeutic hydrogel platform. Results: The formed Fe3O4 nanoparticles can be effectively taken up by CT26 cancer cells and induce the death of CT26 cells in vitro under NIR laser irradiation because of their excellent photothermal property. In addition, Fe3O4 nanoparticle-loaded ALG hydrogels show negligible cytotoxicity at the studied concentration range, but can significantly kill cancer cells after PTT effect. Conclusion: This ALG-based hydrogel platform provides a valuable reference for subsequent in vivo studies and other related studies on Fe3O4 nanoparticle-loaded hydrogels.

Multifunctional Fe3O4 Nanoparticles Filled Polydopamine Hollow Rods for Antibacterial Biofilm Treatment.

This work reports the use of mesoporous silica rods as templates for the step-wise preparation of multifunctional Fe3O4 NPs filled polydopamine hollow rods (Fe3O4@PDA HR). The capacity of as-synthesized Fe3O4@PDA HR as a new drug carrier platform was assessed by its loading and the triggered release of fosfomycin under various stimulations. It was found that the release of fosfomycin was pH dependent with ~89% of fosfomycin being released in pH 5 after 24 h, which was 2-fold higher than that in pH 7. The magnetic properties of Fe3O4 NPs and the photothermal properties of PDA enabled the triggered release of fosfomycin upon the exposure to rotational magnetic field, or NIR laser irradiation. Additionally, the capability of using multifunctional Fe3O4@PDA HR to eliminate preformed bacterial biofilm was demonstrated. Upon exposure to the rotational magnetic field, the biomass of a preformed biofilm was significantly reduced by 65.3% after a 20 min treatment with Fe3O4@PDA HR. Again, due to the excellent photothermal properties of PDA, a dramatic biomass decline (72.5%) was achieved after 10 min of laser exposure. This study offers an alternative approach of using drug carrier platform as a physical mean to kill pathogenic bacteria along with its traditional use for drug delivery.

Ferric oxide nanosheet-engineered Mg alloy for synergetic osteosarcoma photothermal/chemodynamic therapy

• Fe 3 O 4 nanosheets were prepared on Mg alloy by transforming Mg-Fe LDH. • Fe 3 O 4 nanosheets are composed of dense nanoparticles. • Fe 3 O 4 nanosheets enhanced corrosion resistance and biocompatibility of Mg alloy. • Fe 3 O 4 nanosheet-engineered Mg alloy showed PTT/CDT synergetic antitumor property. Osteosarcoma (OS) is a malignant tumor with a high rate of recurrence. Recently, biodegradable Mg-based implants have become a new therapeutic platform for bone-related diseases. However, poor biosafety and deficient intelligent tumor-killing ability of Mg-based implants are still the main challenges for the precise treatment of OS. Herein, based on the excellent catalytic and photothermal conversion properties of nanozyme ferric oxide (Fe 3 O 4 ), a novel two-step hydrothermal method for in situ preparation of Fe 3 O 4 nanosheets on the surface of plasma electrolytic oxidation (PEO)-treated Mg alloy using Mg-Fe layered double hydroxides (Mg-Fe LDH) as precursor was proposed. Compared with Mg alloy, there were no obvious corrosion cracks on the surface of Fe 3 O 4 nanosheets-coated Mg alloy (Fe 3 O 4 -NS) immersed in 0.9 wt.% NaCl for 14 days, which demonstrated the corrosion resistance of Mg alloy was significantly enhanced. Cytocompatibility experiments and hemolysis assay confirmed the great biocompatibility of Fe 3 O 4 -NS, especially, hemolysis ratio was lower than 1%. Meanwhile, Fe 3 O 4 -NS presented excellent catalytic oxidation capacity in the presence of H 2 O 2 , and its temperature can significantly increase from 27 °C to approximately 56 °C under NIR irradiation. Therefore, intelligent responsive Fe 3 O 4 nanosheets-engineered Mg-based implants demonstrated excellent antitumor properties in vivo and in vitro due to their photothermal and chemodynamic synergetic effects. This study provides a novel approach for the preparation of Fe 3 O 4 coatings on the surface of Mg alloys and a new strategy for the treatment of OS.

Ultralarge Pixel Array Photothermal Film based on 3D Self-Suspended Microbridge Structure for Infrared Scene Projection.

Infrared emitter is highly desirable for applications in infrared imaging and infrared stealth technology. It is also a core device in infrared scene generation. Light-driven photothermal film has attracted considerable interest due to its outstanding photothermal properties and easy fabrication. However, the existing photothermal films suffer from low photothermal conversion efficiency (PCE) as well as small sizes. The improvement of the PCE is usually achieved at the expense of dynamic frame rate. Here, this work designs and fabricates a photothermal film based on 3D self-suspended microbridge structure. Silicon (Si) microbridges are introduced into each microstructure to manipulate the thermal conductivity of the films. By optimizing the parameters of the Si microbridges, the high PCE and fast frame rate are both achieved. Moreover, the 3D structure microbridge film is 4-inch in diameter, forming an ultralarge array with over 2200 × 2200 pixels. Finally, a high PCE infrared scene projector is realized based on this photothermal film. A visible image is projected on the film, the 3D-microstructured photothermal film absorbs the visible light and emits an infrared image same as the visible one with high resolution and fast frame rate due to the excellent photothermal properties.

Synergistic Photocatalytic and Photothermal Antibacterial Activity of (In, Nb) and (Al, Nb) Co‐Doped TiO2 Ceramics

Photodynamic and photothermal therapies are promising approaches to deal with implant‐associated infection. However, the efficacy of monotherapy is often insufficient, posing the importance of combinatory therapies. Herein, the AlNbTiO2 and InNbTiO2 ceramics are prepared by (In, Nb) and (Al, Nb) co‐doping into TiO2 ceramics via a solid‐phase reaction. The co‐doping enhances the visible/ near infrared (NIR) light adsorption and endows the TiO2 with excellent photocatalytic and photothermal properties, which is likely due to the formation of large defect‐dipole clusters and oxygen vacancies. The antibacterial efficacy of AlNbTiO2/InNbTiO2 ceramics is 99.04%/98.56% against E. coli and 95.06%/93.68% against S. aureus within 10 min under 808 nm NIR light irradiation, which is ascribed to the synergistic action of enhanced photocatalytic and photothermal effects. Cell culture experiments using MC3T3‐E1 cells prove that the viability and proliferation of MC3T3‐E1 cultured on TiO2 and AlNbTiO2/InNbTiO2 ceramics are comparable, emphasizing their excellent biocompatibility as well. This study suggests that AlNbTiO2/InNbTiO2 has potential application as an antibacterial bioceramic or coating for orthopedic implants.

Structural Significance of Hydrophobic and Hydrogen Bonding Interaction for Nanoscale Hybridization of Antiseptic Miramistin Molecules with Molybdenum Disulfide Monolayers

This paper reports an easy route to immobilize the antiseptic drug miramistin (MR) molecules between the sheets of molybdenum disulfide, known for excellent photothermal properties. Two hybrid layered compounds (LCs) with regularly alternating monolayers of MR and MoS2, differing in thickness of organic layer are prepared and studied by powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), density functional theory (DFT) calculations and quantum theory of atoms in molecules (QTAIM) topological analysis. The obtained structural models elucidate the noncovalent interaction network of MR molecules confined in the two-dimensional spacing surrounded by sulfide sheets. It emerged that the characteristic folded geometry of MR molecule previously evidenced for pure miramistin is preserved in the hybrid structures. Quantification of the energetics of bonding interactions unveils that the most important contribution to structure stabilization of both compounds is provided by the weak but numerous CH…S bonding contacts. They are accompanied by the intra- and inter-molecular interactions within the MR layers, with dominating bonding effect of intermolecular hydrophobic interaction. The results obtained in the models provide a comprehensive understanding of the driving forces controlling the assembly of MR and MoS2 and may lead towards the development of novel promising MoS2-based photothermal therapeutic agents.

Bacteria-based multiplex system eradicates recurrent infections with drug-resistant bacteria via photothermal killing and protective immunity elicitation

BackgroundThe high mortality associated with drug-resistant bacterial infections is an intractable clinical problem resulting from the low susceptibility of these bacteria to antibiotics and the high incidence of recurrent infections.MethodsHerein, a photosynthetic bacteria-based multiplex system (Rp@Al) composed of natural Rhodopseudomonas palustris (Rp) and Food and Drug Administration-approved aluminum (Al) adjuvant, was developed to combat drug-resistant bacterial infections and prevent their recurrence. We examined its photothermal performance and in vitro and in vivo antibacterial ability; revealed its protective immunomodulatory effect; verified its preventative effect on recurrent infections; and demonstrated the system’s safety.ResultsRp@Al exhibits excellent photothermal properties with an effective elimination of methicillin-resistant Staphylococcus aureus (MRSA). In addition, Rp@Al enhances dendritic cell activation and further triggers a T helper 1 (TH1)/TH2 immune response, resulting in pathogen-specific immunological memory against recurrent MRSA infection. Upon second infection, Rp@Al-treated mice show significantly lower bacterial burden, faster abscess recovery, and higher survival under near-lethal infection doses than control mice.ConclusionsThis innovative multiplex system, with superior photothermal and immunomodulatory effects, presents great potential for the treatment and prevention of drug-resistant bacterial infections.Graphical

Smart plasmonic Ag/Ag2O/ZnO nanocomposite with promising photothermal and photodynamic antibacterial activity under 600 nm visible light illumination

• Smart plasmonic Ag/Ag 2 O/ZnO nanocomposite was fabricated. • Excellent photothermal conversion property under 600 nm light illuminating. • Ag serves as a plasmonic material enhancing the light absorption in the visible region. • Promising antibacterial activity upon 600 nm illumination against Enterococcus faecalis . Photoactivated antibacterial activity is a very promising strategy to fight bacteria without inducing bacterial resistance. This contribution combines the photodynamic and photothermal properties along with plasmonic effect in a single nanocomposite to effectively kill bacteria. Plasmonic Ag/p-Ag 2 O/n-ZnO heterojunction nanocomposites with well-defined morphologies are synthesized via solution combustion using glycine and thyme extract as fuels. Ag/Ag 2 O/ZnO shows excellent photothermal conversion behavior under 600 nm light illuminating. ESR analysis confirms the production of reactive species (ROS) under 600 nm. Ag acts as plasmonic material enhancing the light absorption in the visible region. FT-IR confirms the presence of thyme-related function groups on the surface of the prepared nanocomposite which also contribute to enhancing the antibacterial activity. Ag/Ag 2 O/ZnO shows promising antibacterial activity under 600 nm illumination against Enterococcus faecalis . Moreover, the nanocomposite shows excellent antibacterial activity against C. albicans and S. epidermidis in the dark. The efficient bacterial killing under 600 nm light illumination is attributed to the synergetic effects among photothermal, photodynamic, and plasmonic effects. The antibacterial activity in the dark is due to the intrinsic antibacterial activity of Ag, ZnO, and Ag 2 O along with thyme plant extract. Cytotoxicity of Ag/Ag 2 O/ZnO on Huh-7 human liver cancer cells line is also investigated and the IC 50 values calculated are 112.9 and 313 μg/mL for the Ag/Ag 2 O/ZnO samples prepared using 3ml (3AgZn) and 7 ml AgNO 3 (7AgZn) respectively.

Construction of Artificial Controllable Aggregation Trojan Horse-Like Nanoplatform for Enhanced NIR-II Photothermal Therapy.

Promoting the aggregation of nanoprobes at tumor sites and realizing precise imaging and treatment of tumors is still one of the important problems to be solved in the field of nanomedicine. Poly-2-phenylbenzobisthiazole (PB) is a novel conjugated polymer with good biocompatibility, excellent photothermal properties in the second near-infrared region (NIR-II), but poor water dispersibility. Herein, a novel self-assembly/polymerization two-in-one strategy was proposed to prepare a new family of poly-2-phenyl-benzobisthiazole-based nanoparticles. Because the hydrophobic polymer PB was well "camouflaged" in the hydrophilic polyphenol-metal networks, the prepared "Trojan horse-like" nanoparticle TF-PB exhibited good water dispersibility. Besides, TF-PB can play a role as a contrast agent for photoacoustic and magnetic resonance dual-modality imaging. When deferoxamine was artificially applied and interacted with TF-PB, the polyphenol-metal networks disintegrated and the hydrophobic material PB was exposed and started hydrophobic aggregation. Thus, it can be applied for precise enhanced photothermal therapy (PTT) in the NIR-II. Meanwhile, the aggregation process enabled non-invasive, fast, and accurate real-time monitoring by self-enhancing photoacoustic imaging. This work has realized the artificially controllable aggregation of photothermal materials in the tumor site, solved the limitations of traditional PTT, and also has good application prospects in clinical therapy.

Green Light-Triggerable Chemo-Photothermal Activity of Cytarabine-Loaded Polymer Carbon Dots: Mechanism and Preliminary In Vitro Evaluation.

Carbon-based nanostructures are attracting a lot of attention because of their very low toxicity, excellent visible light-triggered optical and photothermal properties, and intriguing applications. Currently, the development of multifunctional carbon-based nanostructures for a synergistic chemo-photothermal approach is a challenging topic for the advancement of cancer treatment. Here, we report an unprecedented example of photoresponsive carbon-based polymer dots (CPDs-PNM) obtained by a one-pot thermal process from poly(N-isopropylacrylamide) (PNIPAM) without using organic solvent and additional reagents. The CPDs-PNM nanostructures were characterized by spectroscopic techniques, transmission electron microscopy, and atomic force microscopy. The CPDs-PNM exhibited high photothermal conversion efficiency, lower critical solution temperature (LCST) behavior, and good cytarabine (arabinosyl cytosine, AraC) loading capacity (62.3%). The formation of a CPDs-PNM/AraC adduct and photothermal-controlled drug release, triggered by green light excitation, were demonstrated by spectroscopic techniques, and the drug-polymer interaction and drug release mechanism were well supported by modeling simulation calculations. The cellular uptake of empty and AraC-loaded CPDs-PNM was imaged by confocal laser scanning microscopy. In vitro experiments evidenced that CPDs-PNM did not affect the viability of neuroblastoma cells, while the CPDs-PNM/AraC adduct under light irradiation exhibited significantly higher toxicity than AraC alone by a combined chemo-photothermal effect.

A NIR-mediated MXene@CuS composite for eliminating osteosarcoma and promoting osteogenesis

Recently, increasing attention is being paid to malignant bone tumors that originate from postoperative recurrence and bone defect problems. It is urgent to develop a multi-functional platform to achieve efficient tumor treatment and bone regeneration. Therefore, a multifunctional nanoparticle of copper sulfide-modified Ti3C2TX MXene decorated with dopamine (PDA) was designed. The excellent photothermal properties and anti-tumor ability to kill osteosarcoma cells (Saos-2 cells) rapidly within 10 min under 808 nm laser irradiation were presented due to the combination of photothermal and photodynamic effects of nanoparticles. Further, the modification of PDA imparts nanoparticles with favorable osteogenic activity.

Functionalized superhydrophobic MWCNT/PEI nanocomposite film with anti-icing and photo-/electrothermal deicing properties

Ice accumulation often threatens the safety of human life and property. How to effectively solve the problem of solid surface icing has been the research work of many researchers. However, how to prepare superhydrophobic and anti-icing film with multi-strategy collaborative deicing is still facing great challenges. In this paper, a design strategy of photothermal and electrothermal superhydrophobic nanocomposite film based on polyetherimide (PEI) was proposed. Multi-walled carbon nanotubes (MWCNT) were dispersed in PEI matrix by solution blending method, and a lotus leaf like rectangular micropillar array was constructed on the surface of the film by laser etching technology. Then, the surface was fluorinated to further reduce the surface energy. Finally, a kind of MWCNT/PEI nanocomposite film with passive anti-icing and active deicing with photothermal and electrothermal collaboration was successfully prepared. The freezing time of droplets on MWCNT/PEI nanocomposite film is about 6.7 times longer than that of pure PEI film. This film exhibits excellent superhydrophobicity (CA = 156.6°), while also having excellent photothermal and electrothermal conversion properties. In addition, we also conducted various tests on MWCNT/PEI nanocomposite film to verify its reliability in the actual application environment. The MWCNT/PEI nanocomposite film with the function of anti-icing and photothermal and electrothermal active deicing is expected to solve the problem of solid surface icing in daily life, and also provides a new idea for the development of a new generation of anti-icing/deicing film.

Oxygen vacancies-mediated CuO@N-doped carbon nanocomposites for non-radical-dominated photothermal catalytic degradation of contaminants

Efficient molecular oxygen activation (MOA) is a critical step for most of the environmental catalysis applications for generating reactive oxygen species (ROS), which is often limited by the lack of energy to excite electrons. The emergence of photothermal catalyst provides an opportunity to make effective use of solar energy to energize electrons for boosting activation of molecular oxygen. Herein, CuO nanoparticles wrapped into nitrogen-doped carbon nanocomposites (CuO@NCs) with abundant oxygen vacancies (OVs) were prepared through a facile one-step synthesis using carboxymethyl chitosan hydrogel as a template. The as-obtained CuO@NCs exhibited excellent photothermal catalytic properties under visible-light irradiation to achieve efficient molecular oxygen activation, thus allowing the effective degradation of bisphenol F (BPF) in complex aqueous environments and actual water matrices. Density functional theory (DFT) calculations reveal that both the enhanced properties of OVs for molecular oxygen adsorption and the accelerated properties of graphitic N for electron transfer contribute significantly to the MOA and charge separation efficiency, resulting in a large amount of ROS. Molecular oxygen is converted to superoxide (·O2−) and ultimately to singlet oxygen (1O2), which is the dominant ROS responsible for contaminants degradation. Additionally, a photothermal catalytic degradation pathway of BPF was proposed based on the product detection and theoretical calculations. This study provides an effective method for the in-situ fabrication of metal@N-doped carbon nanocomposite photothermal catalysts and elucidates the mechanism of the photothermal catalytic activation of molecular oxygen for contaminants degradation, providing a promising approach for making effective use of solar energy for environmental remediation.

Thermosensitive Microfibril Cellulose/MnO2 Membrane: Dual Network Structure, Photothermal Smart Modulation for Switchable Emulsion Separation

Frequently occurring oil spill accidents have caused tremendous pollution of the ecological environment. Although various oil–water separation strategies have been developed, the design of efficient oil–water separation materials still remains a significant challenge. In this study, we report a controllable and scalable method for the fabrication of wettability-switchable membranes (MCPP) that achieved a smart temperature response and efficient emulsion separation. The pore structure of the membrane was precisely controlled by the amount of natural microfibril cellulose and MnO2 nanowires. The tensile strength of the membrane was significantly increased to 2.4 MPa with the introduction of poly(vinylidene difluoride). The temperature sensitivity of poly(N-isopropylacrylamide) resulted in a reversible wettability switch of the MCPP membrane, achieving temperature-controlled smart separation for emulsions. Interestingly, the excellent photothermal conversion properties of MnO2 nanowires realized the switch of membrane surface wettability and oil viscosity reduction, further increasing the emulsion separation performance. The MCPP membrane shows high separation permeance (O/W, 4300–5000 L m–2 h–1 bar–1; W/O, 5000–17000 L m–2 h–1 bar–1) and separation efficiency (>99.4%) for a variety of emulsions. The scalable preparation, smart temperature-sensitive wettability switch, excellent emulsion separation performance, and good reusability provide the basis for the practical application of this membrane in water purification fields.

Accurate immunochromatography with colorimetric/photothermal dual-readout to detect nitrofurazone metabolites

The single-signal colorimetric immunochromatography assay (ICA) is becoming increasing inadequate in dealing with current detection requirement, e.g., more flexible, accurate, and sensitive detection. Herein, by introducing tannic acid (TA) to exfoliate molybdenum disulfide (MoS2) nanosheets and selecting anisotropic gold nanorods (AuNRs) as the nanocarriers, a dual-signal nanocomposite of TA/MoS2 @AuNRs was steadily constructed. The nanocomposite possesses excellent signal transmission and photothermal properties because of the high NIR absorption cross-section and signal intensity of AuNRs as well as strong photothermal conversion efficiency of MoS2. The TA/MoS2 @AuNRs were used to prepare immunoprobes and then applied in the ICA. With 2-nitrobenzaldehyde semicarbazone (2-NPSEM) as the model analyte, the obtained competitive photothermal/colorimetric dual-signal readout ICA (PCICA) can monitor NPSEM colorimetrically and photothermally with a calculated sensitivity of 0.267 and 0.180 ng mL−1, respectively. Furthermore, the application feasibility of the immunoassay was further evaluated by measuring SEM in the honey sample with satisfactory recoveries ranging from 83.35% to 107.14% and coefficient of variation (CV) ranging from 0.12% to 7.63%. As a result, by introducing TA to exfoliate MoS2 nanosheet, this work has proposed a more stable photothermal/colorimetric platform and provide an invigorating pathway for the appliance of MoS2-related photothermal materials in point-of-care immunoassays.