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1.
Ufuk Kilic Matthew Hilfiker Alexander Ruder Rene Feder Eva Schubert Mathias Schubert Christos Argyropoulos 《Advanced functional materials》2021,31(20):2010329
Designing broadband enhanced chirality is of strong interest to the emerging fields of chiral chemistry and sensing, or to control the spin orbital momentum of photons in recently introduced nanophotonic chiral quantum and classical optical applications. However, chiral light-matter interactions have an extremely weak nature, are difficult to control and enhance, and cannot be made tunable or broadband. In addition, planar ultrathin nanophotonic structures to achieve strong, broadband, and tunable chirality at the technologically important visible to ultraviolet spectrum still remain elusive. Here, these important problems are tackled by experimentally demonstrating and theoretically verifying spectrally tunable, extremely large, and broadband chiroptical response by nanohelical metamaterials. The reported new designs of all-dielectric and dielectric-metallic (hybrid) plasmonic metamaterials permit the largest and broadest ever measured chiral Kuhn's dissymmetry factor achieved by a large-scale nanophotonic structure. In addition, the strong circular dichroism of the presented bottom-up fabricated optical metamaterials can be tuned by varying their dimensions and proportions between their dielectric and plasmonic helical subsections. The currently demonstrated ultrathin optical metamaterials are expected to provide a substantial boost to the developing field of chiroptics leading to significantly enhanced and broadband chiral light-matter interactions at the nanoscale. 相似文献
2.
Laura Fabris Mark Dante Thuc‐Quyen Nguyen Jeffrey B.‐H. Tok Guillermo C. Bazan 《Advanced functional materials》2008,18(17):2518-2525
We report here “aptatags,” which consist of aptamer‐modified silver nanoparticles (NPs) held together by an optical reporter. It is possible to use these materials to design a heterogeneous method for protein identification that takes advantage of the Raman signal enhancement by metallic nanostructures and the recognition capabilities of aptamers. Aptatags are formed by linking silver NPs with an organic dithiol molecule, followed by surface modification with thiolated single‐stranded DNA (ssDNA) corresponding to the sequence of the aptamer probe. The sensing surface involves a silver layer containing the thiolated capturing aptamer and mercaptohexadecanoic acid to minimize nonspecific binding. The overall process provides excellent selectivity and sensitivity. Detailed characterization of the sensing surface by SERS maps and atomic force microscopy was carried out to understand how structural features lead to signal generation. 相似文献
3.
Yujie Yang Donghui Li Jinlong Cai Hui Wang Chuanhang Guo Shang Wen Wei Li Tao Wang Dan Liu 《Advanced functional materials》2023,33(10):2209643
Organic semiconductor nanoparticles (NPs) are attractive photocatalysts to produce hydrogen from water splitting. Herein, a ternary strategy of incorporating crystalline n-type molecule IDMIC-4F into the host system made of p-type polymer PM6 and n-type molecule ITCC-M is demonstrated. ITCC-M and IDMIC-4F form compact alloy-like composite with shorter lattice spacing in the ternary p/n heterojunction NPs, resulting in enhanced exciton dissociation and charge transfer characteristics. As the result, an unprecedented hydrogen evolution rate (HER) of 307 mmol h−1 g−1 and a maximum apparent quantum efficiency of 5.9% at 600 nm are achieved in the optimized ternary NPs (PM6:ITCC-M:IDMIC-4F = 1:1.3:0.2), which is among the highest HER from organic photocatalysts to the best of the authors’ knowledge. The alloy-like composite also improves the operational stability of ternary NP photocatalysts. This study shows that synergizing two compatible n-type small molecules to form alloy-like composite is a promising approach to design novel organic photocatalysts for boosting the photocatalytic hydrogen evolution efficiency. 相似文献
4.
This article reports for the first time a novel category of hollow organic@inorganic hybrid two‐layered nanoparticles (NPs), in which the inner layer is formed by optically active helical polyacetylene, and the outer layer by silica. Such NPs show remarkable optical activity and are successfully used for enantioselective crystallization. To prepare such NPs, n‐butyl acrylate undergoes radical polymerization to first form poly(n‐butyl acrylate) (PBA) cores two shells by catalytic polymerization of substituted acetylene and sol–gel approach of TEOS (tetraethyl orthosilicate), respectively. Removal of the PBA cores provides the expected hollow core/shell NPs. The intense dircular dichroism (CD) effects demonstrate that the hollow chiral NPs possess considerable optical activity, arising from the helical substituted polyacetylenes forming the inner layer. The hollow NPs are further used as chiral templates to induce enantioselective crystallization of racemic alanines, demonstrating the significant potential applications of the hollow chiral NPs in chiral technologies. Also of particular significance is the detailed process of the induced crystallization observed by TEM. The strategy for preparing the hollow hybrid chiral NPs should be highlighted since it combines free radical polymerization and catalytic polymerization with sol–gel process in a single system, by which numerous advanced materials will be accessible. 相似文献
5.
Chiroptical properties of pure inorganic material have been achieved by dispersing small amounts of achiral Ag nanoparticles into highly ordered chiral mesoporous silica. There are three types of chirality in chiral mesoporous silica: i) the helical hexagonal surface, ii) the helical pore orientation, and iii) the helical arrangement of aminopropyl groups on the surface of the mesopores, all of which impart plasmonic circular dichroism and have been investigated by introducing Ag nanoparticles into the as‐made, calcined and extracted chiral mesoporous silica, respectively. The three types of optical response originate from asymmetric plasmon‐plasmon interactions of achiral Ag nanoparticles in three types of chiral environments. Among the three sources of chirality, the helical pore orientation was considered to be predominantly responsible for the optical response owing to the high efficiency of nanoscale chirality. Interestingly, large Ag nanoparticles aggregation as a result of calcination still resulted in a strong optical activity, even the chiral mesostructure was destroyed completely. Rather than the pitch length, the length of helical channel was more effective for increasing the intensity of plasmonic circular dichroism due to longitudinal propagation of Ag nanoparticles along helical channel. Such novel chiral inorganic material will bring new opportunities in non‐linear optics, biosensors and chiral recognition. 相似文献
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7.
Shuangmei Wu Chen Xu Yiwen Zhu Liang Zheng Ludan Zhang Yang Hu Bingran Yu Yuguang Wang Fu-Jian Xu 《Advanced functional materials》2021,31(33):2103591
Efficient antimicrobials are urgently needed for the treatment of bacterial biofilms due to their resistance to traditional drugs. Photodynamic therapy (PDT) is a new strategy that has been used to combat bacteria and biofilms. Cationic photosensitizers, particularly cationic photodynamic nanoagents, are usually chosen to enhance photodynamic antimicrobial activity. However, positively charged nanoparticles (NPs) are beneficial to cellular internalization, which causes increased cell cytotoxicity. Herein, a pH-sensitive photodynamic nanosystem is designed. Rose Bengal (RB) polydopamine (PDA) NPs are decorated in a layer-by-layer fashion with polymyxin B (PMB) and gluconic acid (GA) to generate functionally adaptive NPs (RB@PMB@GA NPs). RB@PMB@GA NPs remain negative at physiological pH and exhibit good biocompatibility. When RB@PMB@GA NPs are exposed to an acidic infectious environment, the surface charge of the NPs is, in turn, positively charged as a result of pH-sensitive electrostatic interactions. This surface charge conversion allows the RB@PMB@GA to effectively bind to the surfaces of bacteria and enhance photoinactivation efficiency against gram-negative bacteria. Most importantly, RB@PMB@GA NPs exhibit good biofilm penetration and eradication under acidic conditions. Furthermore, RB@PMB@GA NPs efficiently eliminate biofilm infections in vivo. This study provides a promising strategy for safely treating biofilm-associated infections in vivo. 相似文献
8.
Hyuk‐Seong Seo Seong‐Eun Kim Jin‐Seung Park Jong‐Hwan Lee Ki‐Yeon Yang Heon Lee Kyung Eun Lee Sung‐Sik Han Jeewon Lee 《Advanced functional materials》2010,20(23):4055-4061
Here a novel technique is reported to construct a three‐dimensional (3D) array of well‐defined and controllable multilayered nanostructures of proteins that is based on alternate layer‐by‐layer assembly of bacterial protein nanoparticles and DNA on a patterned array of gold dots. This is the first report on protein‐based multilayer stacking, which has the following significant advantages over conventional multilayer assemblies: 1) avoiding hazardous chemicals, the multilayer assembly is implemented in aqueous solution under mild temperature and pH conditions over a relatively short period; 2) direct multilayer growth from designated position is possible by controlling the aspect ratio; 3) multicomponent stacking can be easily performed through alternate stacking of different building blocks (in this case protein nanoparticles); and 4) a wide variety of 3D arrays can be constructed using various functionalized protein nanoparticles that are easily prepared through a simple genetic engineering approach. In this study, as a proof of concept, the developed 3D and patterned arrays of protein nanoparticle multilayers are successfully applied to the multiplexed bioassays of breast and colorectal cancer markers. 相似文献
9.
Wenjing Zhao Weixuan Zhang Rong‐Yao Wang Yinglu Ji Xiaochun Wu Xiangdong Zhang 《Advanced functional materials》2019,29(20)
Reversible photocontrol of dynamic chirality in self‐assembly systems is of great importance in exploitations of artificial nanomachines for scientific and industrious applications. Here, a new strategy is proposed for achieving optically chiral controls based on photoswitchable plasmonic nanostructures. Chiral plasmonic nanoassemblies that are responsive to optomechanical perturbations exerted by circular polarized light (CPL) in the visible (vis)/near infrared (NIR) region are designed. The reversible photoswitching between opposite chiral states is verified by circular dichroism (CD) spectral signals. Theoretical simulations reveal the key role of optical torques in driving this chiral switching. By regulating light polarization or tuning light frequency to excite different plasmonic modes of the nanostructures, such an optomechanically driven chiral switching can enable a directed mirror‐symmetry breaking and selective chiral amplification in nanoassemblies. This plasmon‐based photoswitching nanosystem can operate at the optical transparent window, showing particular advantages over most of the molecular photoswitches for applications in living systems. 相似文献
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11.
Dong Cui Pengcheng Li Xu Zhen Jingchao Li Yuyan Jiang Aixi Yu Xiang Hu Kanyi Pu 《Advanced functional materials》2019,29(38)
Photoacoustic (PA) agents with biomarker‐activated signals are developed to enhance the signal‐to‐background ratios (SBRs) for in vivo imaging; however, their SBRs still heavily rely on the concentration difference of biomarkers between diseased and normal tissues. By contrast, external stimuli can provide a remote way to noninvasively control the signal generation from the PA agents and in turn enhance SBR, which are less exploited. This study reports the development of thermoresponsive semiconducting polymer brush with poly(N,N‐dimethylacrylamide)‐r‐(hydroxypropyl acrylate) (PDMA‐r‐HPA) grafts for contrast‐enhanced in vivo imaging. Such a polymer is amphiphilic and can self‐assemble into the nanoparticle (termed as SPNph1) in an aqueous medium, and has lower critical solution temperatures (LCSTs) at 48 °C. Thus, SPNph1 not only has higher photothermal conversion efficiency than the control polymer without PDMA‐r‐HPA grafts, but also can undergo phase separation to form large nanoparticles, leading to enhanced PA signals above LCST. The thermoresponsive PA property of SPNph1 enables in situ remote manipulation of PA signals by photoirradiation to further enhance the tumor SBR. Thus, this study introduces a new generation of organic PA agents with thermoresponsive signal for high‐contrast in vivo imaging. 相似文献
12.
Johan Karlsson Stephany Y. Tzeng Shayan Hemmati Kathryn M. Luly Olivia Choi Yuan Rui David R. Wilson Kristen L. Kozielski Alfredo Quiñones-Hinojosa Jordan J. Green 《Advanced functional materials》2021,31(17):2009768
Clinical translation of polymer-based nanocarriers for systemic delivery of RNA has been limited due to poor colloidal stability in the blood stream and intracellular delivery of the RNA to the cytosol. To address these limitations, this study reports a new strategy incorporating photocrosslinking of bioreducible nanoparticles for improved stability extracellularly and rapid release of RNA intracellularly. In this design, the polymeric nanocarriers contain ester bonds for hydrolytic degradation and disulfide bonds for environmentally triggered small interfering RNA (siRNA) release in the cytosol. These photocrosslinked bioreducible nanoparticles (XbNPs) have a shielded surface charge, reduced adsorption of serum proteins, and enable superior siRNA-mediated knockdown in both glioma and melanoma cells in high-serum conditions compared to non-crosslinked formulations. Mechanistically, XbNPs promote cellular uptake and the presence of secondary and tertiary amines enables efficient endosomal escape. Following systemic administration, XbNPs facilitate targeting of cancer cells and tissue-mediated siRNA delivery beyond the liver, unlike conventional nanoparticle-based delivery. These attributes of XbNPs facilitate robust siRNA-mediated knockdown in vivo in melanoma tumors colonized in the lungs following systemic administration. Thus, biodegradable polymeric nanoparticles, via photocrosslinking, demonstrate extended colloidal stability and efficient delivery of RNA therapeutics under physiological conditions, and thereby potentially advance systemic delivery technologies for nucleic acid-based therapeutics. 相似文献
13.
Jianli Zhao Marina Spasova Zi‐An Li Michael Zharnikov 《Advanced functional materials》2011,21(24):4724-4735
Monodisperse Co nanoparticles (NPs), stabilized by organic coating have been synthesized, and their immobilization on a variety of self‐assembled monolayers (SAMs) bearing different terminal groups and on SAM‐based chemical templates has been studied. The NPs had an average diameter of ~10 nm and consisted of hcp cobalt covered by a thin (~1 nm) oxide film. They exhibited pronounced ferromagnetic properties with a blocking temperature above 380 K, which is unusual for the given NP size and is presumably related to the high magnetocrystalline anisotropy associated with the crystallographic perfection of the NPs. The NPs were found to attach selectively to the SAMs bearing the thiol tail group, whereas no stable immobilization to other SAMs, over the electrostatic forces, could be achieved. Finally, based on the results for the individual SAMs, high‐contrast 2D structures of the Co NPs were fabricated on SAM‐based chemical templates on both micro‐ and nanometer length scales. The templates were prepared by irradiation‐promoted exchange reaction lithography, taking an OH‐terminated aliphatic SAMs as the primary template and thiol‐bearing aromatic molecules as the substituents. 相似文献
14.
Hongbian Li Xuchun Gui Luhui Zhang Chunyan Ji Yichi Zhang Pengzhan Sun Jinquan Wei Kunlin Wang Hongwei Zhu Dehai Wu Anyuan Cao 《Advanced functional materials》2011,21(18):3439-3445
The movement of nanoparticles across cell membranes in a controlled manner is important for developing applications related to filtration, penetration, and biological systems. Here, the tunable transport of metal nanoparticle suspensions with well‐defined particle sizes and surface groups through a ≈1 mm‐thick porous carbon nanotube sponge filter is reported. Au particles with a relatively large diameter (40 nm) alone are easily trapped by the nanotube sponge even in a dilute water flow, but they can quickly pass through the sponges by the addition of much smaller particles (4 nm) to the suspension. A mechanistic study shows that the dominating interaction mode between Au particles and the sponge is physical trapping within the nanotube networks rather than Coulomb attraction. In the nanoparticle mixture, surface groups on the small particles tend to form hydrogen bonds with groups on large particles, thereby increasing interparticle distances, and preventing formation of severe agglomerates; large particles can therefore move across interconnected nanotubes more smoothly. It might be possible to switch the transport of many different nanoparticles across porous media on and off by adding or removing smaller particles of the same type. 相似文献
15.
Electrically Oscillating Plasmonic Nanoparticles for Enhanced DNA Vaccination against Hepatitis C Virus
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Mohamed Shehata Draz Ying‐Jie Wang Frank Fanqing Chen Yuhong Xu Hadi Shafiee 《Advanced functional materials》2017,27(5)
The promise of DNA vaccines is far‐reaching. However, the development of potent immunization methods remains a key challenge for its use in clinical applications. Here, an approach for in vivo DNA vaccination by electrically activated plasmonic Au nanoparticles is reported. The electrical excitation of plasmonic nanoparticles can drive vibrational and dipole‐like oscillations that are able to disrupt nearby cell membranes. In combination with their intrinsic ability to focus and magnify the electric field on the surface of cells, Au nanoparticles allow enhanced cell poration and facilitate the uptake of DNA vaccine. Mice immunized with this approach showed up to 100‐fold higher gene expression compared to control treatments (without nanoparticles) and exhibited significantly increased levels of both antibody and cellular immune responses against a model hepatitis C virus DNA vaccine. This approach can be tuned to establish controlled and targeted delivery of different types of therapeutic molecules into cells and live animals as well. 相似文献
16.
Minfeng Huo Peilei Liu Linlin Zhang Chenyang Wei Liying Wang Yu Chen Jianlin Shi 《Advanced functional materials》2021,31(16):2010196
The hypoxic hallmark of tumor has aroused substantial burdens on a variety of therapeutic modalities including photodynamic therapy (PDT). Recently, biological oxygen evolution enabled by photosynthetic cyanobacterial cells has emerged as one of the most advanced and promising tissue oxygenation strategies, which is particularly beneficial for in situ tumor-PDT. Herein, a near infrared-driven PDT platform based on the photosynthetic cyanobacterial cells hybridized with photosensitizer rose bengal (RB)-loaded upconversion nanoparticles, named as UR-Cyan cells, is reported. Upon the irradiation of 980 nm laser and its upconversions to shorter wavelengths, the formulated UR-Cyan cells are both photosynthetically active for oxygen production and photosensitive for the subsequent singlet oxygen generation by the photosensitizer, resulting in enhanced and sustainable PDT efficacy against tumor cells/tissues. The present design offers a practical approach to conquer the hypoxic burden of PDT operations against a wide range of pathological lesions with excellent biocompatibility and clinical promises. 相似文献
17.
Xufan Li Tongxiang Fan Han Zhou Suk‐Kwun Chow Wang Zhang Di Zhang Qixin Guo Hiroshi Ogawa 《Advanced functional materials》2009,19(1):45-56
The unique structure of green leaves endows them with an extremely high light‐harvesting efficiency. In this work, green leaves are applied as biotemplates to synthesize morph‐TiO2. The structural features favorable for light harvesting from the macro‐ to the nanoscale are replicated in morph‐TiO2 through a two‐step infiltration process and the N contained in the original leaves is self‐doped into the resulting samples. The absorbance intensities within the visible‐light range of morph‐TiO2 derived from different leaves increase by 103–258% and the band‐gap‐absorption onsets at the edge of the UV and visible‐light range show a red‐shift of 25–100 nm compared to those in TiO2 without the template. The photocatalytic activity of morph‐TiO2 is also improved, as proven by an electron paramagnetic resonance (EPR) study and degradation of rhodamine dye under irradiation with UV and visible light. The present work, as a new strategy, is of far‐reaching significance in learning from nature, driving us to make full use of the most‐abundant resources and structure‐introduced functions endowed by nature, opening up possibilities for extensive study of the physical and chemical properties of morph‐structured oxides and extending their potential for use in applications such as solar cells, photocatalysts, photoelectrical devices, and photoinduced sensors. 相似文献
18.
Jiewei Chen Ting Zhang Jingli Wang Ning Zhang Wei Ji Shuyun Zhou Yang Chai 《Advanced functional materials》2021,31(40):2104192
Charge-based field-effect transistors (FETs) greatly suffer from unavoidable carrier scattering and heat dissipation. Analogous to valley degree of freedom in semiconductors, chiral anomaly current in Weyl/Dirac semimetals is theoretically predicted to be nearly nondissipative over long distances, but still lacks experimental ways to efficiently control its transport. Here, field-effect chirality devices are demonstrated with Dirac semimetal PtSe2, in which its Fermi level is close to the Dirac point in the conduction band owing to intrinsic defects. The chiral anomaly is further corroborated by the planar Hall effect and nonlocal valley transport measurement, which can also be effectively modulated by external fields, showing robust nonlocal valley transport with micrometer diffusion length. Similar to charge-based FETs, the chiral conductivity in PtSe2 devices can be modulated by electrostatic gating with an ON/OFF ratio of more than 103. Basic logic functions in the devices are also demonstrated with electric and magnetic fields as input signals. 相似文献
19.
Jing Cheng Zhang Mu Ku Chen Yao Liang Xiao Hong Muting Wang Yijun Cheng Xiaoyuan Liu Din Ping Tsai Stella W. Pang 《Advanced functional materials》2023,33(49):2306422
The polarization of light is a valuable information channel that has been studied extensively in optical devices. There has been limited progress in developing low-refractive index contrast and large-scale chiral meta-devices that are easy to integrate and mass-produce. In this image, a chiral imaging meta-device with a large area and broadband chirality control is experimentally demonstrated. The centimeter-scale Moiré meta-device is achieved using nanoimprint technology. The Poynting vector and singularity features in the near field and chiral optical response in the far field are discussed. The proposed Moiré meta-devices can achieve circular dichroism (CD) of more than 10%. Further chiral imaging harnessing CD mechanisms are demonstrated, which may lead to significant potential in various fields, including encryption and security, materials science, biochemistry, and medicine. 相似文献
20.
Shape Control of Mn3O4 Nanoparticles on Nitrogen‐Doped Graphene for Enhanced Oxygen Reduction Activity
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Jingjing Duan Sheng Chen Sheng Dai Shi Zhang Qiao 《Advanced functional materials》2014,24(14):2072-2078
Three kinds of Mn3O4 nanoparticles with different shapes (spheres, cubes, and ellipsoids) are selectively grown on nitrogen‐doped graphene sheets through a two‐step liquid‐phase procedure. These non‐precious hybrid materials display an excellent ORR activity and good durability. The mesoporous microstructure, nitrogen doping, and strong bonding between metal species and doped graphene are found to facilitate the ORR catalytic process. Among these three kinds of Mn3O4 particles, the ellipsoidal particles on nitrogen‐doped graphene exhibit the highest ORR activity with a more positive onset‐potential of –0.13 V (close to that of Pt/C, –0.09 V) and a higher kinetic limiting current density (JK) of 11.69 mA cm–2 at –0.60 V. It is found that the ORR performance of hybrid materials can be correlated to the shape of Mn3O4 nanocrystals, and specifically to the exposed crystalline facets associated with a given shape. The shape dependence of Mn3O4 nanoparticles integrated with nitrogen‐doped graphene on the ORR performance, reported here for the first time, may advance the development of fuel cells and metal‐air batteries. 相似文献