Amplified Self‐Immolative Release of Small Molecules by Spatial Isolation of Reactive Groups on DNA‐Minimal Architectures

Triggering the release of small molecules in response to unique biomarkers is important for applications in drug delivery and biodetection. Due to low quantities of biomarker, amplifying release is necessary to gain appreciable responses. Nucleic acids have been used for both their biomarker‐recognition properties and as stimuli, notably in amplified small‐molecule release by nucleic‐acid‐templated catalysis (NATC). The multiple components and reversibility of NATC, however, make it difficult to apply in vivo. Herein, we report the use of the hybridization chain reaction (HCR) for the amplified, conditional release of small molecules from standalone nanodevices. We couple HCR with a DNA‐templated reaction resulting in the amplified, immolative release of small molecules. We integrate the HCR components into single nanodevices as DNA tracks and spherical nucleic acids, spatially isolating reactive groups until triggering. This could be applied to biosensing, imaging, and drug delivery.     

DNA Origami Post‐Processing by CRISPR‐Cas12a

Customizable nanostructures built through the DNA‐origami technique hold tremendous promise in nanomaterial fabrication and biotechnology. Despite the cutting‐edge tools for DNA‐origami design and preparation, it remains challenging to separate structural components of an architecture built from—thus held together by—a continuous scaffold strand, which in turn limits the modularity and function of the DNA‐origami devices. To address this challenge, here we present an enzymatic method to clean up and reconfigure DNA‐origami structures. We target single‐stranded (ss) regions of DNA‐origami structures and remove them with CRISPR‐Cas12a, a hyper‐active ssDNA endonuclease without sequence specificity. We demonstrate the utility of this facile, selective post‐processing method on DNA structures with various geometrical and mechanical properties, realizing intricate structures and structural transformations that were previously difficult to engineer. Given the biocompatibility of Cas12a‐like enzymes, this versatile tool may be programmed in the future to operate functional nanodevices in cells.     

Amplified Self-Immolative Release of Small Molecules by Spatial Isolation of Reactive Groups on DNA-Minimal Architectures

Triggering the release of small molecules in response to unique biomarkers is important for applications in drug delivery and biodetection. Due to low quantities of biomarker, amplifying release is necessary to gain appreciable responses. Nucleic acids have been used for both their biomarker-recognition properties and as stimuli, notably in amplified small-molecule release by nucleic-acid-templated catalysis (NATC). The multiple components and reversibility of NATC, however, make it difficult to apply in vivo. Herein, we report the use of the hybridization chain reaction (HCR) for the amplified, conditional release of small molecules from standalone nanodevices. We couple HCR with a DNA-templated reaction resulting in the amplified, immolative release of small molecules. We integrate the HCR components into single nanodevices as DNA tracks and spherical nucleic acids, spatially isolating reactive groups until triggering. This could be applied to biosensing, imaging, and drug delivery.     

Judicious Choice of N-Heterocycles for the Realization of Sky-Blue- to Green-Emitting Carbazolylgold(III) C^C^N Complexes and Their Applications for Organic Light-Emitting Devices

A new class of sky-blue- to green-emitting carbazolylgold(III) C^C^N complexes containing pyrazole or benzimidazole moieties has been successfully designed and synthesized. Through the judicious choice of the N-heterocycles in the cyclometalating ligand and the tailor-made carbazole moieties, maximum photoluminescence quantum yields of 0.52 and 0.39 have been realized in the green- and sky-blue-emitting complexes, respectively. Solution-processed and vacuum-deposited organic light-emitting devices (OLEDs) based on the benzimidazole-containing complexes have been prepared. The sky-blue-emitting device shows an emission peaking at 484 nm with a narrow full-width at half-maximum of 57 nm (2244 cm⁻¹), demonstrating the potential of this class of complexes in the application of OLEDs with high color purity. In addition, high maximum external quantum efficiencies of 12.3 % and a long operational half-lifetime of over 5300 h at 100 cd m⁻² have been achieved in the vacuum-deposited green-emitting devices.     

Influence of chain length of prepolymers in permanent memory effect of PDLC assessed by solid-state NMR

ABSTRACT

The relationship between linear chain (ethylene oxide units) length of polymerisable monomers with morphology, electro-optical properties and ¹³C nuclear magnetic resonance (NMR) spectroscopy of the corresponding polymer-dispersed liquid crystal (PDLC) films was investigated. The preferred liquid crystal molecule alignment and permanent memory effect of PDLC were greatly influenced by the length of the molecular chain of prepolymers to be incorporated as a polymer matrix. By increasing the number of ethylene oxide in prepolymer chain and maintaining the number of functionalities (polymerisable groups in each monomer molecule), the permanent memory effect of PDLC increased, as proved by solid-state ¹³C NMR spectroscopy.     

功能性可拉伸有机电子器件的研究进展

可拉伸有机电子器件具有高机械稳定性、优异的电学稳定性、低成本和生物兼容性好等优点,是未来电子器件发展的重要方向.功能性可拉伸有机电子器件更是为可穿戴和可植入设备、智能医疗以及软体机器人等新兴高技术领域提供了新的研究思路.本文综述了近年来功能性可拉伸有机电子器件的研究进展,包括场效应、光电、存储以及传感等有机晶体管,发光二极管、交流电致发光、发光电化学电池等有机光电器件,太阳能电池、超级电容器、纳米发电机等有机能源存储与转换器件,压力、应变、触觉、温度、气体等有机传感器,忆阻器、磁存储、仿突触存储等有机存储器,以及其他集成电路系统元件,最后就功能性可拉伸有机电子器件存在的科学问题与未来的发展方向提出了建议.     

A Novel Continuous Industrial Process for Producing Hydroxyapatite Nanoparticles

Fluidinova, a recent start‐up high technology engineering company, has developed and is now commercializing a novel continuous industrial reactor NETmix for the manufacture of high added value products, such as nanomaterials, microemulsions, and pharmaceutical products. Through this technology, Fluidinova, in cooperation with Instituto de Engenharia Biomédica, has developed and patented the industrial process for the synthesis of a new high quality product consisting of hydroxyapatite nanoparticles with extremely high purity and crystallinity to be used as biocompatible nanomaterial for biomedical and pharmaceutical applications, to improve the quality of the already existing hydroxyapatite based medical devices, such as bone grafts, coated implants, and drug delivery systems.     

Static and dynamic dielectric effects in the vicinity of the isotropic to nematic phase transition in 7CB

Static and dynamic dielectric measurements were performed with very high accuracy on a mesogenic compound n‐heptylcyanobiphenyl (7CB) in the isotropic (I) and nematic (N) phases. The critical‐like temperature behaviour of the static permittivity of isotropic 7CB in the vicinity of the I–N phase transition can be described with the critical exponent close to 0.5, indicating the tricritical nature of the transition. Anomalously slow rotational diffusion (subdiffusion), characterized by a fractal value of the diffusion exponent α, is observed in the vicinity of the I–N transition with a lambda‐like profile of the exponent temperature dependence.     

Output power enhancement of 100% for quaternary GaInAsSb/AlGaAsSb semiconductor disc lasers grown with a sequential growth scheme

Molecular beam epitaxial (MBE) growth and lasing operation of quaternary GaInAsSb/AlGaAsSb-based optically-pumped vertical-external-cavity surface-emitting lasers (VECSEL) emitting at a wavelength of 2.0 μm are reported. MBE growth of such structures is particularly challenging as it requires, apart from the large total thickness of the epitaxial layer stack of 10–12 μm a change of group-III fluxes for the growth of AlAsSb and low Al-content AlGaAsSb. Two different growth schemes are compared. The first one is the conventional growth procedure in which the wafer remains in the growth chamber and the growth is interrupted at the interfaces before and after the active region to adjust the group-III cell temperatures for different flux settings. At the interfaces where the growth had to be interrupted, secondary-ion mass-spectrometry revealed the unintentional incorporation of In at a concentration equivalent to 1–2 monolayers. Here we introduce a new growth procedure—the sequential growth scheme where each section of the VECSEL is grown separately, and after the growth of a section, the sample is taken out of the growth chamber and stored in the buffer chamber while the group-III cell temperatures are adjusted. After the new group-III fluxes have been stabilized, the wafer is transferred back into the growth chamber and the next section of the laser is grown. This way the unintentional incorporation of In at interfaces between different sections of the VECSEL structure can be avoided. A comparison of nominally identical VECSEL structures grown within the same growth campaign using the two different growth procedures reveals an increase of the maximum output power of nearly 100% for a 2.0 μm emitting VECSEL structure grown with the sequential growth scheme accompanied by an improvement of the optical-to-optical power conversion efficiency from 14.4% to 21.5%.     

High open-circuit voltage single-layer polybithiophene-based photovoltaic devices

We report the construction of single-polymer-layer photovoltaic devices using polybithiophene thin films synthesized in propylene carbonate, using fluorine-doped tin-oxide as substrates. Polybithiophene films show high organization of molecular dipoles, leading to an open-circuit voltage of 2 V when photovoltaic devices with aluminum top contacts are constructed. An erratum to this article can be found at