基于主客体识别作用构建的电化学发光传感器检测丹参中汞离子

使用联吡啶钌(Ru(bpy)32+)/β-环糊精-金纳米粒子(β-CD-AuNPs)/全氟磺酸(Nafion)复合物和二茂铁标记(Fc)的DNA探针(Fc-DNA)构建了电化学发光(Electrochemiluminescence,ECL)生物传感器,将其用于检测中药材丹参中的汞离子。 该传感器包含ECL发光基底和ECL强度开关两部分,将Ru(bpy)32+/β-CD-AuNPs/Nafion组装到玻碳电极(GCE)上构成发光基底,产生稳定的ECL信号;Fc-DNA探针作为ECL信号开关,通过分子识别策略设计,利用β-CD与Fc的主客体相互作用与β-CD-AuNPs相连。 该检测方法和以往的汞离子检测方法相比,具有背景信号低、选择性高、仪器简单、操作快速等特点。 该 “Off-On” 电致化学发光生物传感器在0.04~800 ng/mL范围内对Hg²⁺具有良好的线性响应,检测限为0.02 ng/mL(S/N=3)。     

Studies on Isosorbide-enhanced Biodegradable Poly(ethylene succinate)

To improve the mechanical properties of bio-based poly(ethylene succinate),the sugar monomer isosorbide,whicli is relatively easy to obtain,was used as a copolymerized third monomer to synthesize poly(ethyleneco-isosorbide succinate),a 100%biomass copolyester.The effects of isosorbide on the crystallinity and thermal properties of copolyester were studied by nuclear magnetic resonancefH NMR),differential scanning calorimeter(DSC),and thermogravimetric(TG).Owing to its distinct rigid bicyclic structure,isosorbide can improve the glass transition temperature of the copolyester and decrease the crystallization rate,as well as accelerate the hydrolysis of the copolyester.Simultaneously,the introduction of isosorbide can effectively improve the antistatic properties of copolyester.     

Reconfigurable Bioinspired Framework Nucleic Acid Nanoplatform Dynamically Manipulated in Living Cells for Subcellular Imaging

In nature, the formation of spider silk fibers begins with dimerizing the pH‐sensitive N‐terminal domains of silk proteins (spidroins) upon lowering pH, and provides a natural masterpiece for programmable assembly. Inspired by the similarity of pH‐dependent dimerization behaviors, introduced here is an i‐motif‐guided model to mimic the initial step of spidroin assembly at the subcellular level. A framework nucleic acid (FNA) nanoplatform is designed using two tetrahedral DNA nanostructures (TDNs) with different branched vertexes carrying a bimolecular i‐motif and a split ATP aptamer. Once TDNs enter acidic lysosomes within living cells, they assemble into a heterodimeric architecture, thereby enabling the formation of a larger‐size framework and meanwhile subcellular imaging in response to endogenous ATP, which can be dynamically manipulated by adjusting intracellular pH and ATP levels with external drug stimuli.     

电喷雾电离质谱法研究环肽对HIV-1调控区DNA的识别及其相关碎裂机理和稳定性

利用电喷雾电离质谱(ESI-MS)和二级质谱(MS/MS)研究了六种结构不同的环五肽, 环七肽以及环十肽与HIV-1调控区DNA的非共价键相互作用. 在研究中比较了不同识别分子与靶序列DNA结合的强弱, 发现环七肽CP5对靶点DNA具有高亲合性的结合. 用MS/MS法研究了环肽与DNA复合物的碎裂机理; 用升温实验研究了其热稳定性, 发现与CP5结合后能提高HIV-1双螺旋DNA的热稳定性.     

Facial synthesis of carbon-coated ZnFe<Subscript>2</Subscript>O<Subscript>4</Subscript>/graphene and their enhanced lithium storage properties

Carbon-coated ZnFe₂O₄ spheres with sizes of ~110–180 nm anchored on graphene nanosheets (ZF@C/G) are successfully prepared and applied as anode materials for lithium ion batteries (LIBs). The obtained ZF@C/G presents an initial discharge capacity of 1235 mAh g^?1 and maintains a reversible capacity of 775 mAh g^?1 after 150 cycles at a current density of 500 mA g^?1. After being tested at 2 A g^?1 for 700 cycles, the capacity still retains 617 mAh g^?1. The enhanced electrochemical performances can be attributed to the synergetic role of graphene and uniform carbon coating (~3–6 nm), which can inhibit the volume expansion, prevent the pulverization/aggregation upon prolonged cycling, and facilitate the electron transfer between carbon-coated ZnFe₂O₄ spheres. The electrochemical results suggest that the synthesized ZF@C/G nanostructures are promising electrode materials for high-performance lithium ion batteries.

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Graphical abstract ?

     

基于离子液体修饰介孔硅的免标记电化学免疫测定双组分肿瘤标志物

建立了一种可同时检测双组分肿瘤标志物的免标记电化学免疫测定方法,检测了人血清样品中癌胚抗原（CEA）和甲胎蛋白（AFP）的含量. 在实验中,我们首先将二种电化学底物,二茂铁甲酸（FCA）和亚甲基蓝（MB）,分别结合在离子液体（IL）修饰的介孔硅（MPS）的孔道内,制备FCA-IL-MPS和MB-IL-MPS复合材料;然后将免疫探针涂覆在掺铟氧化锡（ITO）电极表面的不同部分;最后将CEA单克隆抗体（anti-CEA）和AFP单克隆抗体（anti-AFP）分别负载到两种材料的孔内,制得CEA和AFP的免标记免疫探针（anti-CEA/FCA-IL-MPS,anti-AFP/MB-IL-MPS）,组装得到双组分的免标记免疫传感器. 当该免疫传感器在含有抗原的样液中温育后,CEA和AFP抗原通过特异性免疫反应而结合到MPS孔道内. 由于形成的免疫复合物不导电且有一定的空间位阻,所以对电极表面的电子转移产生了阻碍. 根据ITO不同位置上响应电流的变化实现对CEA和AFP含量的同时测定. 本方法对CEA和AFP的检测线性范围分别为0.5～80 ng·mL^-1和0.5～100 ng·mL^-1,检测限分别为0.1 ng·mL^-1和0.1 ng·mL^-1（S/N=3）. 离子液体具有高导电率,能实现所构建体系信号的放大,使制备的免疫传感器具有良好的灵敏度.     

L-o cto-algebras

L-octo-algebra with 8 operations as the Lie algebraic analogue of octo-algebra such that the sum of 8 operations is a Lie algebra is discussed. Any octo-algebra is an L-octo-algebra. The relationships among L-octo-algebras, L-quadri-algebras, L-dendriform algebras, pre-Lie algebras and Lie algebras are given. The close relationships between L-octo-algebras and some interesting structures like Rota-Baxter operators, classical Yang-Baxter equations and some bilinear forms satisfying certain conditions are given also.     

Long‐Range Chirality Recognition of a Polar Molecule on Au(111)

Chiral molecular self‐assemblies were usually achieved using short‐range intermolecular interactions, such as hydrogen‐, metal–organic, and covalent bonding. However, unavoidable surface defects, such as step edges, surface reconstructions, or site dislocations may limit the applicability of short‐range chirality recognition. Long‐range chirality recognition on surfaces would be an appealing but challenging strategy for chiral reservation across surface defects at long distances. Now, long‐range chirality recognition is presented between neighboring 3‐bromo‐naphthalen‐2‐ol (BNOL) stripes on an inert Au(111) surface across the herringbone reconstruction as investigated by STM and DFT calculations. The key to achieving such recognition is the herringbone reconstruction‐induced local dipole accumulation at the edges of the BNOL stripes. The neighboring stripes are then forced to adopt the same chirality to create the opposite edged dipoles and neutralize the neighbored dipole moments.     

Long-Range Chirality Recognition of a Polar Molecule on Au(111)

Chiral molecular self-assemblies were usually achieved using short-range intermolecular interactions, such as hydrogen-, metal–organic, and covalent bonding. However, unavoidable surface defects, such as step edges, surface reconstructions, or site dislocations may limit the applicability of short-range chirality recognition. Long-range chirality recognition on surfaces would be an appealing but challenging strategy for chiral reservation across surface defects at long distances. Now, long-range chirality recognition is presented between neighboring 3-bromo-naphthalen-2-ol (BNOL) stripes on an inert Au(111) surface across the herringbone reconstruction as investigated by STM and DFT calculations. The key to achieving such recognition is the herringbone reconstruction-induced local dipole accumulation at the edges of the BNOL stripes. The neighboring stripes are then forced to adopt the same chirality to create the opposite edged dipoles and neutralize the neighbored dipole moments.     

Ga-vacancy-induced room-temperature ferromagnetic and adjusted-band-gap behaviors in GaN nanoparticles

Room-temperature ferromagnetism has been found in Ga-deficient GaN grown using the direct reaction of Ga \(_{2}\) O \(_{3}\) powder with NH \(_{3}\) gas. The observed magnetism in GaN induced by Ga vacancies is investigated both experimentally and theoretically. First-principles calculations reveal that the spontaneous spin polarization is created by the 3.0  \(\mu _\mathrm{B}\) local moment for GaN and magnetism originates from the polarization of the unpaired 2 \(p\) electrons of N surrounding the Ga vacancy. At the same time, the band gap can be also adjusted by changing the Ga-vacancy concentration.