Mechanically Robust,Elastic, and Healable Ionogels for Highly Sensitive Ultra-Durable Ionic Skins

The fabrication of highly durable skin-mimicking sensors remains challenging because of the unavoidable fatigue and physical damage that sensors are subjected to in practical applications. In this study, ultra-durable ionic skins (I-skins) with excellent healability and high sensitivity are fabricated by impregnating ionic liquids (ILs) into a mechanically robust poly(urea-urethane) (PU) network. The PU network is composed of crystallized poly(ε-caprolactone) and flexible poly(ethylene glycol) that are dynamically cross-linked with hindered urea bonds and hydrogen bonds. Such a design endows the resultant ionogels with high mechanical strength, good elasticity, Young's modulus similar to that of natural skin, and excellent healability. The ionogel-based I-skins exhibit a high sensitivity to a wide range of strains (0.1–300%) and pressures (0.1–20 kPa). Importantly, the I-skins show a highly reproducible electrical response over 10 000 uninterrupted strain cycles. The sensing performance of the I-skins stored in open air for 200 days is almost the same as that of the freshly prepared I-skin. The fractured I-skins can be easily healed by heating at 65 °C that restores their original ultra-durable sensing performance. The long-term durability of the I-skins is attributed to the combination of non-volatility of the ILs, excellent healability, and well-designed mechanical properties.     

Nanobodies and Nanocrystals: Highly Sensitive Quantum Dot‐Based Homogeneous FRET Immunoassay for Serum‐Based EGFR Detection

Semiconductor quantum dot nanocrystals (QDs) for optical biosensing applications often contain thick polyethylene glycol (PEG)‐based coatings in order to retain the advantageous QD properties in biological media such as blood, serum or plasma. On the other hand, the application of QDs in Förster resonance energy transfer (FRET) immunoassays, one of the most sensitive and most common fluorescence‐based techniques for non‐competitive homogeneous biomarker diagnostics, is limited by such thick coatings due to the increased donor‐acceptor distance. In particular, the combination with large IgG antibodies usually leads to distances well beyond the common FRET range of approximately 1 to 10 nm. Herein, time‐gated detection of Tb‐to‐QD FRET for background suppression and an increased FRET range is combined with single domain antibodies (or nanobodies) for a reduced distance in order to realize highly sensitive QD‐based FRET immunoassays. The “(nano)²” immunoassay (combination of nanocrystals and nanobodies) is performed on a commercial clinical fluorescence plate reader and provides sub‐nanomolar (few ng/mL) detection limits of soluble epidermal growth factor receptor (EGFR) in 50 μL buffer or serum samples. Apart from the first demonstration of using nanobodies for FRET‐based immunoassays, the extremely low and clinically relevant detection limits of EGFR demonstrate the direct applicability of the (nano)^2‐ assay to fast and sensitive biomarker detection in clinical diagnostics.     

A Self-Powered,Highly Embedded and Sensitive Tribo-Label-Sensor for the Fast and Stable Label Printer

Label-sensor is an essential component of the label printer which is becoming a most significant tool for the development of Internet of Things(IoT). However, some drawbacks of the traditional infrared label-sensor make the printer fail to realize the high-speed recognition of labels as well as stable printing. Herein, we propose a selfpowered and highly sensitive tribo-label-sensor(TLS) for accurate label identification, positioning and counting by embedding triboelectric nanogenerator into the...     

多孔和高分散材料比表面积、孔结构标准物质研究进展

多孔和高分散材料比表面积、孔结构标准物质在相应仪器设备的校准、分析方法的确认、产品质量的控制等方面具有重要的作用。本文中简述了物理吸附法、压汞法测量多孔和高分散材料比表面积、孔结构的基本原理以及国内外相应分析测量标准的现状,重点讨论了国外多孔和高分散材料物理吸附法和压汞法比表面积、孔结构标准物质的研究现状,指出了我国相应标准物质研制存在的不足以及今后应努力的方向。     

碳纳米管与PVA协同加强光谱探针并应用于灵敏测定肝素钠

提出将碳纳米管(CNTs)作为一种新型分析增效试剂用于加强光谱探针,研究了其与水溶性大分子增效试剂聚乙烯醇(PVA)的协同增敏机理,并应用于乙基紫(EV)光度法测定肝素钠(Heparin,Hep)的体系中.在此缔合物显色体系中,含芳香环大分子的EV通过π～π作用于CNTs的管壁上.增大了有色物质的吸光面积;PVA的加入提高了CNTs及离子缔合物的分散性.结果表明,在CNTs与PVA复配的影响下,EV与Hep在pH为6.5的Britton-Robinson(B-R)缓冲溶液中形成稳定的紫红色缔合物后在640nm处发生明显的褪色,△Amax提高了330.7%..肝素钠浓度在0～2.5mg/L范围内与△A成正比,回归方程为△A=-0.006 0.360 C(mg/L),表观摩尔吸光系数ε=4.29 × 106L·mol-1·cm-1,R=0.9991.在最佳实验条件下,对肝素钠注射液效价进行了测定.     

Graphene Oxide,Highly Reduced Graphene Oxide,and Graphene: Versatile Building Blocks for Carbon‐Based Materials

Isolated graphene, a nanometer‐thick two‐dimensional analog of fullerenes and carbon nanotubes, has recently sparked great excitement in the scientific community given its excellent mechanical and electronic properties. Particularly attractive is the availability of bulk quantities of graphene as both colloidal dispersions and powders, which enables the facile fabrication of many carbon‐based materials. The fact that such large amounts of graphene are most easily produced via the reduction of graphene oxide—oxygenated graphene sheets covered with epoxy, hydroxyl, and carboxyl groups—offers tremendous opportunities for access to functionalized graphene‐based materials. Both graphene oxide and graphene can be processed into a wide variety of novel materials with distinctly different morphological features, where the carbonaceous nanosheets can serve as either the sole component, as in papers and thin films, or as fillers in polymer and/or inorganic nanocomposites. This Review summarizes techniques for preparing such advanced materials via stable graphene oxide, highly reduced graphene oxide, and graphene dispersions in aqueous and organic media. The excellent mechanical and electronic properties of the resulting materials are highlighted with a forward outlook on their applications.     

Light Confinement Effect Induced Highly Sensitive,Self‐Driven Near‐Infrared Photodetector and Image Sensor Based on Multilayer PdSe2/Pyramid Si Heterojunction

In this study, a highly sensitive and self‐driven near‐infrared (NIR) light photodetector based on PdSe₂/pyramid Si heterojunction arrays, which are fabricated through simple selenization of predeposited Pd nanofilm on black Si, is demonstrated. The as‐fabricated hybrid device exhibits excellent photoresponse performance in terms of a large on/off ratio of 1.6 × 10⁵, a responsivity of 456 mA W^?1, and a high specific detectivity of up to 9.97 × 10¹³ Jones under 980 nm illumination at zero bias. Such a relatively high sensitivity can be ascribed to the light trapping effect of the pyramid microstructure, which is confirmed by numerical modeling based on finite‐difference time domain. On the other hand, thanks to the broad optical absorption properties of PdSe₂, the as‐fabricated device also exhibits obvious sensitivity to other NIR illuminations with wavelengths of 1300, 1550, and 1650 nm, which is beyond the photoresponse range of Si‐based devices. It is also found that the PdSe₂/pyramid Si heterojunction device can also function as an NIR light sensor, which can readily record both “tree” and “house” images produced by 980 and 1300 nm illumination, respectively.     

基于事故树和动态灰色关联方法的机坪事故人为因素分析研究

对机坪事故运用事故树进行定性分析后,再对引起基本事件的人为失误原因进行分类,最后利用动态灰色关联方法分析这些人为失误因素的影响程度。某机场实例研究得出,该机坪事故的人为失误主要原因为组织管理和个人原因。此研究得出的理论依据对完善和改进机坪安全管理有针对性的实用意义。