Using the DNA origami technique, we constructed a DNA nanodevice functionalized with small interfering RNA (siRNA) within its inner cavity and the chemotherapeutic drug doxorubicin (DOX), ...intercalated in the DNA duplexes. The incorporation of disulfide bonds allows the triggered mechanical opening and release of siRNA in response to intracellular glutathione (GSH) in tumors to knockdown genes key to cancer progression. Combining RNA interference and chemotherapy, the nanodevice induced potent cytotoxicity and tumor growth inhibition, without observable systematic toxicity. Given its autonomous behavior, exceptional designability, potent antitumor activity and marked biocompatibility, this DNA nanodevice represents a promising strategy for precise drug design for cancer therapy.
An autonomous tubular DNA nanodevice is constructed to deliver a chemotherapeutic drug and siRNAs. This nanodevice can realize on‐demand targeting, respond to stimuli in the intracellular environment and release multiple molecular payloads for combined antitumor activity.
Strong light-matter interaction at room temperature is significant for quantum optics, especially for exploring advanced nano-optical devices. We report herein a light-matter interaction in the ...strong coupling regime between plasmons confined within a single isolated bimetallic nanoring or nanocuboid and molecular excitons of J-aggregates under ambient conditions. We show that a bimetallic Au@Ag nanoring possesses larger enhanced electric field distribution than a Au@Ag nanocuboid, which enables bimetallic nanorings to couple with more excitons efficiently and overcome the large dissipation of the hybrid system. A large vacuum Rabi splitting of 200 meV was observed in this Au@Ag nanoring/J-aggregate hybrid. Finite-difference time-domain (FDTD) simulation and theoretical calculation show that there are ∼196 excitons in each Au@Ag nanoring/J-aggregate hybrid contributing to the coupling with a coupling constant of ∼111.3 meV, which is much higher than that of a single Au@Ag nanocuboid. Our work demonstrates that strong coupling can be realized
via
the enlargement of the overlap volume between excitons and plasmons, which can maximize the number of excitons contributing to coupling, giving rise to giant vacuum Rabi splitting. Our result provides additional flexibility to the experimental realization of novel plexcitonic architectures to attain strong coupling in an easily integrated and ultracompact platform.
We report strong plasmon-exciton coupling in bimetallic nanorings and nanocuboids, and demonstrate nanoring possesses larger enhanced electric field distribution, which enables to couple with more excitons, resulting to a larger Rabi splitting.
Here, we report a trap-assisted photomultiplication （PM） phenomenon in solution-processed organic photodetectors （OPDs） using poly（3-hexylthiophene） （P3HT）： indene-C60 bisadduct （ICBA） as the active ...layer. The maximum external quantum efficiency （EQE） is 685% for the device with 2% ICBA doping ratio, which is much higher than that of OPDs with P3HT：ICBA （1：1） as the active layer. The PM phenomenon is attributed to the hole tunneling injection assisted by trapped electron in ICBA near A1 cathode, which can be demonstrated from the EQE spectra and transient photocurrent curves of OPDs with different ICBA doping ratios.
Metal nanoarchitectures fabrication based on DNA assembly has attracted a good deal of attention. DNA nanotechnology enables precise organization of nanoscale objects with extraordinary structural ...programmability. The spatial addressability of DNA nanostructures and sequence-dependent recognition allow functional elements to be precisely positioned; thus, novel functional materials that are difficult to produce using conventional methods could be fabricated. This review focuses on the recent development of the fabrication strategies toward manipulating the shape and morphology of metal nanoparticles and nanoassemblies based on the rational design of DNA structures. DNA-mediated metallization, including DNA-templated conductive nanowire fabrication and sequence-selective metal deposition, etc., is briefly introduced. The modifications of metal nanoparticles (NPs) with DNA and subsequent construction of heterogeneous metal nanoarchitectures are highlighted. Importantly, DNA-assembled dynamic metal nanostructures that are responsive to different stimuli are also discussed as they allow the design of smart and dynamic materials. Meanwhile, the prospects and challenges of these shape-and morphology-controlled strategies are summarized.
The exploitation of strong light–matter interactions in chiral plasmonic nanocavities may enable exceptional physical phenomena and lead to potential applications in nanophotonics, information ...communication, etc. Therefore, a deep understanding of strong light–matter interactions in chiral plasmonic–excitonic (plexcitonic) systems constructed by a chiral plasmonic nanocavity and molecular excitons is urgently needed. Herein, we systematically studied the strong light–matter interactions in gold nanorod-based chiral plexcitonic systems assembled on DNA origami. Rabi splitting and anticrossing behavior were observed in circular dichroism spectra, manifesting chiroptical characteristic hybridization. The bisignate line shape of the circular dichroism (CD) signal allows the accurate discrimination of hybrid modes. A large Rabi splitting of ∼205/∼199 meV for left-handed/right-handed plexcitonic nanosystems meets the criterion of strong coupling. Our work deepens the understanding of light–matter interactions in chiral plexcitonic nanosystems and will facilitate the development of chiral quantum optics and chiroptical devices.
Shape complementarity is of paramount importance in molecular recognition, but has rarely been adopted in the self-assembly of colloidal particles, especially in the case of nanoparticles of ...different shapes. Here, we demonstrated a simple, yet powerful strategy for fabricating gold nanoring-based heterogeneous nanostructures (AuNR-HNs) with well-defined geometries and high yield. The assembly of various geometries of AuNR-HNs is modulated by the shape complementarity of plasmonic nanorings and nanospheres. We also present experimental evidence of dark quadrupolar ring mode excitation in AuNR-HNs through single-particle optical measurements. Our strategy will be beneficial in the study of nanoparticle assembly, photonic element interaction, and the development of plasmon-based optical devices.
Using the DNA origami technique, we constructed a DNA nanodevice functionalized with small interfering RNA (siRNA) within its inner cavity and the chemotherapeutic drug doxorubicin (DOX), ...intercalated in the DNA duplexes. The incorporation of disulfide bonds allows the triggered mechanical opening and release of siRNA in response to intracellular glutathione (GSH) in tumors to knockdown genes key to cancer progression. Combining RNA interference and chemotherapy, the nanodevice induced potent cytotoxicity and tumor growth inhibition, without observable systematic toxicity. Given its autonomous behavior, exceptional designability, potent antitumor activity and marked biocompatibility, this DNA nanodevice represents a promising strategy for precise drug design for cancer therapy.
An autonomous tubular DNA nanodevice is constructed to deliver a chemotherapeutic drug and siRNAs. This nanodevice can realize on‐demand targeting, respond to stimuli in the intracellular environment and release multiple molecular payloads for combined antitumor activity.
A modified chitosan transparent thin membrane (MCTTM) was prepared and used as the adsorbent to investigate the adsorption kinetics due to excellent capacity of removing copper ions in water ...solution. The structure and morphology of MCTTM were characterized by SEM analysis and FTIR analysis. External mass transfer, intra particle diffusion, and pseudo-first and pseudo-second order models were used to describe the adsorption process. The results obtained from the study illustrated that the adsorption process could be described by the pseudo-second order model, which indicated adsorption process was a chemical adsorption behavior of chelation ion exchange proved by the FTIR and adsorption free energy analysis. External mass transfer and intra particle diffusion processes were the rate-controlling steps.
▶ The reconstruction processes of CH–Mg/Al and CH–Mg/Al/Fe were fast and efficient, but the adsorption of Cr (VI) on CH–Mg/Al/Fe reached equilibrium faster. ▶ The removal mechanism involved not only ...intercalation but also adsorption on external surface of the layers and interlayer anion exchange. ▶ The existence of Fe3+ in Mg/Al calcined hydrotalcite led to the interlayer anion exchange more difficult and it is affected equilibrium amount of Cr (VI) adsorption.
The influence of ferric iron in calcined nano-Mg/Al hydrotalcite on removal of Cr (VI) from aqueous solution was studied from aspects of structure characteristics, adsorption properties and mechanism discussions. The calcined hydrotalcites (CH–Mg/Al and CH–Mg/Al/Fe) were obtained by thermal decomposition of their corresponding precursors and characterized by XRD, TEM, pHPZC and FTIR. The adsorption properties were studied as a function of pH, initial Cr (VI) concentration and contact time. The results showed that the nature of adsorption is endothermic and spontaneous for both CH–Mg/Al and CH–Mg/Al/Fe, but the thermodynamic parameter value changes revealed the addition of Fe3+ is disadvantage to adsorption process and the theoretical saturated adsorption capacity decreased by approximately 10.2mg/g at tested temperatures. The removal mechanism involved not only intercalation but adsorption on external surface of the layers and interlayer anion exchange for both CH–Mg/Al and CH–Mg/Al/Fe. Furthermore, the results also indicated that intercalation accounts for a large proportion during removal process whatever for CH–Mg/Al, or for CH–Mg/Al/Fe. Additionally, the replacement of Al3+ by Fe3+ in CH–Mg/Al led to the interlayer anion exchange more difficult. On the basis of the results, it is concluded that the existence of ferric iron in calcined Mg/Al hydrotalcite is unfavorable to removal of Cr (VI) from aqueous solution.
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