A combined hydrothermal/hydrogen reduction method has been developed for the mass production of helical carbon nanotubes (HCNTs) by the pyrolysis of acetylene at 475 °C in the presence of Fe3O4 ...nanoparticles. The synthesized HCNTs have been characterized by high‐resolution transmission electron microscopy, scanning electron microscopy, X‐ray diffraction analysis, vibrating sample magnetometry, and contact‐angle measurements. The as‐prepared helical‐structured carbon nanotubes have a large specific surface area and high peroxidase‐like activity. Catalysis was found to follow Michaelis–Menten kinetics and the HCNTs showed strong affinity for both H2O2 and 3,3′,5,5′,‐tetramethylbenzidine (TMB). Based on the high activity, the HCNTs were firstly used to develop a biocatalyst and amperometric sensor. At pH 7.0, the constructed amperometric sensor showed a linear range for the detection of H2O2 from 0.5 to 115 μM with a correlation coefficient of 0.999 without the need for an electron‐transfer mediator. Because of their low cost and high stability, these novel metallic HCNTs represent a promising candidate as mimetic enzymes and may find a wide range of new applications, such as in biocatalysis, immunoassay, and environmental monitoring.
Double‐helical‐structured artificial peroxidase: Double‐helical carbon nanotubes (HCNTs) have been synthesized by pyrolysis of acetylene in the presence of Fe3O4 nanoparticles. The HCNTs obtained show peroxidase‐like activity (see figure; TMB=3,3′,5,5′‐ tetramethylbenzidine) and thus mimic enzymes. This property has been exploited in the fabrication of an amperometric sensor for H2O2.
Water pollution and freshwater shortage have deteriorated the global water crisis. Developing sustainable methods to alleviate contaminated water has become an urgent affair. Herein, inspired by ...water transportation and transpiration of natural trees, the authors report an ultralong hydroxyapatite nanowires‐based biomimetic aerogel with vertically aligned channels and multiple functions for continuous flow catalysis, water disinfection, solar energy‐driven water purification, and seawater desalination. Ultralong hydroxyapatite nanowires act as carriers to immobilize catalyst nanoparticles and serve as building blocks to assemble with chitosan to form the biomimetic aerogel with structure‐function integration. Benefiting from the interconnected cellular structure, unidirectional aligned channels, nanowire‐interwoven networked pore wall, and evenly distributed catalyst nanoparticles, the biomimetic aerogel exhibits high catalytic activity (97.6% treatment efficiency) and permeability (1786 L m−2 h−1), excellent recyclability and stability in continuous flow catalytic degradation of methylene blue solely driven by gravity. The biomimetic aerogel exhibits excellent performance for bacteria removal and anti‐biofouling. The superior photothermal conversion and heat confinement properties enable the biomimetic aerogel with a high efficiency (86.7%) for solar energy‐driven seawater desalination and wastewater purification under one sun irradiation. The multifunctional biomimetic aerogel has promising applications in catalytic reactions, wastewater remediation, and environmental engineering.
A tree‐inspired multifunctional aerogel with vertically aligned channels is fabricated from ultralong hydroxyapatite nanowires, immobilized palladium nanoparticles, and chitosan through a unidirectional freeze‐drying approach. The biomimetic aerogel exhibits high performances in gravity‐driven continuous flow catalytic reactions, water disinfection, and solar energy‐driven water purification and seawater desalination.
A highly flexible and nonflammable inorganic hydroxyapatite (HAP) paper made from HAP ultralong nanowires is reported. The paper can be used for printing and writing and is promising for the ...permanent and safe storage of information, such as archives and important documents. The HAP paper is also an excellent and recyclable adsorbent for organic pollutants.
A highly flexible and nonflammable inorganic hydroxyapatite (HAP) paper made from HAP ultralong nanowires is reported. The paper can be used for printing and writing and is promising for the permanent and safe storage of information, such as archives and important documents. The HAP paper is also an excellent and recyclable adsorbent for organic pollutants.
Hypervirulent
(hvKP) has spread globally since first described in the Asian Pacific Rim. It is an invasive variant that differs from the classical
(cKP), with hypermucoviscosity and hypervirulence, ...causing community-acquired infections, including pyogenic liver abscess, pneumonia, meningitis, and endophthalmitis. It utilizes a battery of virulence factors for survival and pathogenesis, such as capsule, siderophores, lipopolysaccharide, fimbriae, outer membrane proteins, and type 6 secretion system, of which the former two are dominant. This review summarizes these hvKP-associated virulence factors in order to understand its molecular pathogenesis and shed light on new strategies to improve the prevention, diagnosis, and treatment of hvKP-causing infection.
The development of versatile nanotheranostic platforms that integrate both diagnostic and therapeutic functions have always been an intractable challenge in precise cancer treatment. Herein, an ...aptamer‐tethered deoxyribonucleic acids‐gold particle (Apt‐DNA‐Au) nanomachine has been developed for in situ imaging and targeted multimodal synergistic therapy of mammary carcinoma. Upon specifically internalized into MCF‐7 cells, the tumor‐related TK1 mRNA activates the Apt‐DNA‐Au nanomachine by DNA strand displacement cascades, resulting in the release of the fluorophore and antisense DNA as well as the aggregation of AuNPs for in situ imaging, suppression of survivin expression and photothermal therapy, respectively. Meanwhile, the controlled released drugs are used for chemotherapy, while under the laser irradiation the loaded photosensitizer produces reactive oxygen species (ROS) for photodynamic therapy. The results confirm that the proposed Apt‐DNA‐Au nanomachine provides a powerful nanotheranostic platform for in situ imaging‐guided combinatorial anticancer therapy.
A multifunctional DNA‐Au nanomachine which can be triggered by endogenous tumor growth‐related TK1 mRNA has been devised as the combinatorial theranostic agent for fluorescence imaging‐guided chemo, genic, photodynamic, and photothermal synergistic targeted therapy of breast cancer. This theranostic nanoplatform achieves the significant inhibition of tumor growth and improvement of therapeutic efficacy through in situ imaging.
Owing to their high natural abundance, low cost, easy availability, and excellent magnetic properties, considerable interest has been devoted to the synthesis and applications of iron oxide ...nanostructured materials. Liquid‐phase synthesis methods are economical and environmentally friendly with low energy consumption and volatile emissions, and as such have received much attention for the preparation of iron oxide nanostructured materials. Herein, the liquid‐phase synthesis methods of iron oxide nanostructured materials including the co‐precipitation method, microemulsion method, conventional hydrothermal and solvothermal methods, microwave‐assisted heating method, sonolysis method, and other methods are summarized and reviewed. Many iron oxide nanostructured materials, self‐assembled nanostructures, and nanocomposites have been successfully prepared, which are of great significance to enhance their structure‐dependent properties and applications. The specific roles of liquid‐phase chemical reaction parameters in regulating the chemical composition, structure, crystallinity, morphology, particle size, and dispersive behavior of the as‐prepared iron oxide nanostructured materials are emphasized. The biomedical, environmental, and electrochemical energy storage applications of iron oxide nanostructured materials are discussed. Finally, challenges and perspectives are proposed for future investigations on the liquid‐phase synthesis and applications of iron oxide nanostructured materials.
Nanostructured iron oxides: This review article summarizes the liquid‐phase synthetic methods for iron oxide nanostructured materials, such as the co‐precipitation method, microemulsion method, conventional hydrothermal and solvothermal methods, microwave‐assisted heating method, sonochemical method, and other methods. In addition, the biomedical, environmental, and electrochemical energy storage applications of iron oxide nanostructured materials are discussed to emphasize their promising applications.
Efficient utilization of abundant solar energy for clean water generation is considered a sustainable and environment friendly approach to mitigate the global water crisis. For this purpose, this ...study reports a flexible fire‐resistant photothermal paper by combining carbon nanotubes (CNTs) and fire‐resistant inorganic paper based on ultralong hydroxyapatite nanowires (HNs) for efficient solar energy‐driven water steam generation and water purification. Benefiting from the structural characteristics of the HN/CNT photothermal paper, the black CNT surface layer exhibits a high light absorbability and photothermal conversion capability, the HN‐based inorganic paper acts as a thermal insulator with a high temperature stability, low thermal conductivity, and interconnected porous structure. By combining these advantages, high water evaporation efficiencies of 83.2% at 1 kW m−2 and 92.8% at 10 kW m−2 are achieved. In addition, the HN/CNT photothermal paper has a stable water evaporation capability during recycling and long‐time usage. The promising potential of the HN/CNT photothermal paper for efficient production of drinkable water from both actual seawater and simulative wastewater samples containing heavy metal ions, dyes, and bacteria is also demonstrated. The highly flexible HN/CNT photothermal paper is promising for application in highly efficient solar energy‐driven seawater desalination and wastewater purification.
Highly flexible fire‐resistant photothermal paper is fabricated using ultralong hydroxyapatite nanowires and carbon nanotubes for highly efficient solar energy‐driven seawater desalination and wastewater purification, it has a high performance in recycling and long‐time usage, and it has promising application in the production of clean drinkable water from seawater and wastewater to mitigate the water scarcity crisis.
Gold‐nanosponge‐based multistimuli‐responsive drug vehicles are constructed for combined chemo‐photothermal therapy with pinpointed drug delivery and release capabilities and minimized nonspecific ...systemic spread of drugs, remarkably enhancing the therapeutic efficiency while minimizing acute side effects.
Solar energy‐driven water evaporation is a promising sustainable strategy to purify seawater and contaminated water. However, developing solar evaporators with high water evaporation rates and ...excellent salt resistance still faces a great challenge. Herein, inspired by the long‐range ordered structure and water transportation capability of lotus stem, a biomimetic aerogel with vertically ordered channels and low water evaporation enthalpy for high‐efficiency solar energy‐driven salt‐resistant seawater desalination and wastewater purification is developed. The biomimetic aerogel consists of ultralong hydroxyapatite nanowires as heat‐insulating skeletons, polydopamine‐modified MXene as a photothermal material with broadband sunlight absorption and high photothermal conversion efficiency, polyacrylamide, and polyvinyl alcohol as reagents to lower the water evaporation enthalpy and as glues to enhance the mechanical performance. The honeycomb porous structure, unidirectionally aligned microchannels, and nanowire/nanosheet/polymer pore wall endow the biomimetic aerogel with excellent mechanical properties, rapid water transportation, and excellent solar water evaporation performance. The biomimetic aerogel exhibits a high water evaporation rate (2.62 kg m−2 h−1) and energy efficiency (93.6%) under one sun irradiation. The superior salt‐rejecting ability of the designed water evaporator enables stable and continuous seawater desalination, which is promising for application in water purification to mitigate the global water crisis.
A lotus stem‐inspired aerogel water evaporator with vertically aligned channels and low water evaporation enthalpy is fabricated using ultralong hydroxyapatite nanowires, polyacrylamide, polyvinyl alcohol, and polydopamine‐modified MXene, which exhibits a high water evaporation rate and high energy efficiency as well as stable and salt‐rejecting seawater desalination.
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