A Novel d-f Heterometallic CdII-EuIII Metal-organic Framework as a Sensitive Luminescent Sensor for the Dual Detection of Ronidazole and 4-Nitrophenol

A novel three-dimensional (3D) d-f heterometallic metal-organic framework (MOF) formulated as [EuCd_1.5L₂(H₂O)₃] · 2H₂O ( 1 ) [H₃L = 5-(4-(tetrazol-5-yl)phenyl)isophthalic acid] was successfully synthesized and characterized. Structural analysis displays that 1 features a 3D (3, 12)-connected framework constructed by [Eu₂Cd₃(tetrazole)₄(COO)₈] units. The powder X-ray diffraction measurement of 1 immersed in different solvents reveals that 1 possess good solvent stability. It is worth noting that 1 displays highly selective detection for ronidazole (RDZ) and 4-nitrophenol (4-NP) through luminescence quenching. The possible mechanism of luminescent sensing is also well discussed.     

Large-Scale Synthesis of MOF-Derived Superporous Carbon Aerogels with Extraordinary Adsorption Capacity for Organic Solvents

Carbon aerogels (CAs) with 3D interconnected networks hold promise for application in areas such as pollutant treatment, energy storage, and electrocatalysis. In spite of this, it remains challenging to synthesize high-performance CAs on a large scale in a simple and sustainable manner. We report an eco-friendly method for the scalable synthesis of ultralight and superporous CAs by using cheap and widely available agarose (AG) biomass as the carbon precursor. Zeolitic imidazolate framework-8 (ZIF-8) with high porosity is introduced into the AG aerogels to increase the specific surface area and enable heteroatom doping. After pyrolysis under inert atmosphere, the ZIF-8/AG-derived nitrogen-doped CAs show a highly interconnected porous mazelike structure with a low density of 24 mg cm⁻³, a high specific surface area of 516 m² g⁻¹, and a large pore volume of 0.58 cm⁻³ g⁻¹. The resulting CAs exhibit significant potential for application in the adsorption of organic pollutants.     

Switchable Polymerization Triggered by Fast and Quantitative Insertion of Carbon Monoxide into Cobalt–Oxygen Bonds

A strategy that uses carbon monoxide (CO) as a molecular trigger to switch the polymerization mechanism of a cobalt Salen complex [salen=(R,R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine] from ring-opening copolymerization (ROCOP) of epoxides/anhydrides to organometallic mediated controlled radical polymerization (OMRP) of acrylates is described. The key phenomenon is a rapid and quantitative insertion of CO into the Co−O bond, allowing for in situ transformation of the ROCOP active species (Salen)Co^III-OR into the OMRP photoinitiator (Salen)Co^III-CO₂R. The proposed mechanism, which involves CO coordination to (Salen)Co^III-OR and subsequent intramolecular rearrangement via migratory insertion has been rationalized by DFT calculations. Regulated by both CO and visible light, on-demand sequence control can be achieved for the one-pot synthesis of polyester-b-polyacrylate diblock copolymers (Đ<1.15).     

Dicyclohepta[ijkl,uvwx]rubicene with Two Pentagons and Two Heptagons as a Stable and Planar Non-benzenoid Nanographene

Polycyclic aromatic hydrocarbons with hexagons/pentagons or hexagons/heptagons have been intensively investigated in recent years, but those with simultaneous presence of hexagons, pentagons and heptagons remain rare. In this paper, we report dicyclohepta[ijkl,uvwx]rubicene ( DHR ), a non-benzenoid isomer of dibenzo[bc,kl]coronene with two pentagons and two heptagons. We developed an efficient and scalable synthetic method for DHR by using Scholl reaction and dehydrogenation. Crystal structure of DHR shows that the benzenoid rings, two pentagons and two heptagons are coplanar. The bond lengths analysis and the ICSS(1)zz and LOL-π calculations indicate that the incorporation of two formal azulene moieties has an effect on the conjugated structure. The π-electrons of benzenoid and pentagon rings are more delocalized. Cyclic voltammetry studies indicate that DHR shows multiple oxidation and reduction potentials. Interestingly, DHR exhibits unusual S₀ to S₂ absorption and abnormal anti-Kasha S₂ to S₀ emission. Moreover, crystals of DHR exhibit semiconducting behaviour with hole mobility up to 0.082 cm² V⁻¹ s⁻¹.     

Facile Synthesis of Hierarchical Nanosized Single-Crystal Aluminophosphate Molecular Sieves from Highly Homogeneous and Concentrated Precursors

The synthesis of hierarchical nanosized zeolite materials without growth modifiers and mesoporogens remains a substantial challenge. Herein, we report a general synthetic approach to produce hierarchical nanosized single-crystal aluminophosphate molecular sieves by preparing highly homogeneous and concentrated precursors and heating at elevated temperatures. Accordingly, aluminophosphate zeotypes of LTA (8-rings), AEL (10-rings), AFI (12-rings), and -CLO (20-rings) topologies, ranging from small to extra-large pores, were synthesized. These materials show exceptional properties, including small crystallites (30–150 nm), good monodispersity, abundant mesopores, and excellent thermal stability. A time-dependent study revealed a non-classical crystallization pathway by particle attachment. This work opens a new avenue for the development of hierarchical nanosized zeolite materials and understanding their crystallization mechanism.     

同源细胞膜包覆智能释药纳米粒用于肝癌靶向治疗

近年来,纳米药物递送系统在癌症治疗方面的应用受到广泛关注。 传统的纳米药物递送系统存在生物相容性差、靶向性缺乏、在肿瘤部位释药缓慢等问题。 本文设计制备了一种同源细胞膜(M)包覆、癌细胞还原微环境控制释药的脂质体纳米粒子(命名为P-ss-G/D/Sf@M)来递送肝癌治疗药物索拉非尼(Sf)用于肝癌的靶向治疗。 利用薄膜水化法结合静电吸附及过膜挤压法制备包覆细胞膜的空白(P-ss-G/D@M)及载药(P-ss-G/D/Sf@M)纳米粒子。 P-ss-G/D/Sf@M对Sf的载药量为7.2%,包封率为79.9%。 体外释药结果显示,P-ss-G/D/Sf@M在还原条件下会加快药物的释放,48 h时药物释放量达到65%以上,较非还原条件下释药量提高了25%。 体外细胞实验结果证明,包覆肝癌细胞膜的纳米粒子更易被肝癌细胞摄取,表现了对肝癌细胞的靶向性,同时在肿瘤细胞高浓度谷胱甘肽(GSH)还原环境作用下,纳米粒子中的二硫键断裂,迅速释放药物,与非还原敏感载药纳米粒子相比,显著抑制肝癌细胞生长,提高细胞凋亡率。 因此,本文制备的同源细胞膜包覆的智能释药载体有可能用于今后的癌症治疗中。     

BaO∙4B2O3∙5H2O纳米材料的制备及其对聚丙烯阻燃性能的热分解动力学方法评价

Borate is considered one of the most important additives for improving the fire-resistance of combustible polymers because of its smoke suppression, low toxicity, and good thermal stability. However, the size of prepared borate is usually in the micrometer range, which makes it difficult to disperse in a polymer matrix, thus hindering its use as fire-retardant material. The preparation and application of borate nanomaterial as flame retardant is considered an effective method. However, the preparation of barium borate nanomaterials as flame retardant has not been reported. In this paper, nanosheets and nanoribbons with different sizes for a new barium borate BaO·4B₂O₃·5H₂O are prepared by hydrothermal method, and characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum (FT-IR), thermogravimetric analysis-differential scanning calorimetry (TG-DSC), and scanning electron microscope (SEM). The flame-retardant properties of polypropylene (PP)/BaO·4B₂O₃·5H₂O composites are investigated by thermogravimetric analysis (TG), differential scanning calorimetry (DSC) thermal analysis methods and limited oxygen index (LOI) method. Considering the near TG mass losses and the near LOI values for PP with 10% prepared BaO·4B₂O₃·5H₂O nanosheet and nanoribbon, their flame-retardant properties need to be further evaluated by non-isothermal decomposition kinetic method. The apparent activation energy for this decomposition reaction was obtained from the slope by plotting ln(β/T_p²) against 1/T_p according to Kissinger's model. With the reduction of TG mass loss, increased heat absorption in DSC under N₂ atmosphere, increased apparent activation energy E_a for the thermal decomposition of PP/BaO·4B₂O₃·5H₂O composite as well as increased LOI value, the flame-retardant performance of prepared BaO·4B₂O₃·5H₂O samples with PP gradually improved from bulk to nanoribbon to nanosheet. This can be attributed to the decrease in the size of BaO·4B₂O₃·5H₂O samples because the smaller sample size leads to improved dispersion and increased contact area with the polymer. The flame-retardant mechanism is discussed by analyzing the after-flame chars of the PP/BaO·4B₂O₃·5H₂O composite in SEM images, which show that the char layer is more compact and continuous for the PP/BaO·4B₂O₃·5H₂O nanosheet composite. The influence of loading BaO·4B₂O₃·5H₂O nanomaterials on the mechanical properties of PP is also tested using a universal material testing machine, in which the PP/BaO·4B₂O₃·5H₂O nanosheet composite has higher tensile strength. The PP/BaO·4B₂O₃·5H₂O nanosheet composite has the best flame-retardant and mechanical properties, which is promising to be developed for the application as flame-retardant material.     

基于杂交链式反应的可视化免疫分析检测癌胚抗原

构建了基于杂交链反应的比色免疫分析方法,实现了对肿瘤标志物癌胚抗原的检测。在抗原-抗体的特异性结合作用下,在磁珠表面构建夹心式免疫复合物,进一步结合杂交链式反应(HCR)作为信号放大策略,将染料曙红Y嵌入至DNA长链中。在可见光的照射下,能使反应底液中的四甲基联苯胺(TMB)氧化,发生明显的颜色变化,由无色变为蓝色,且与癌胚抗原的浓度呈正相关性。在最优实验条件下,癌胚抗原的浓度在1 pg/mL^5 ng/mL范围内呈线性变化,检出限为1 pg/mL。     

有机化学实验在线开放课程设计的探索与实践

针对以往有机化学实验教学中存在的问题及学生所反映的改进期望,在有机化学实验在线开放课程的开发中,充分利用在线课程与网络教育平台,制作了针对性的教学微视频课程和相应的课件,建立了一套完整的测试模式与题库。通过考测机制,促进和强化学生的实验课前预习。而学生在充分预习的基础上,实现实验预习–现象记录–实验报告完整规范化和一体化,相应提高了学习效率。同时,建立了一套相对客观的成绩评估体系并取得了积极的成果。     

涡旋提取-石墨炉原子吸收光谱法测定土壤中有效态镉

土壤作为农业生产的重要载体,是保障农产品质量安全的关键源头。近年来,随着经济的快速发展,土壤中重金属污染问题日益凸显,已成为世界性的重大环境问题之一。目前针对土壤中重金属的调查分析大多处于总量水平,这并不能全面地评价重金属的生态风险,因为土壤-重金属-生物体之间存在复杂的动态相互作用,土壤中只有部分重金属能被生物体吸收,这部分能被生物体吸收利用的元素以特定的形态存在,这种特定的形态被称之为有效态。土壤中重金属能否被植物吸收主要取决于该元素的有效态[1],因此土壤中重金属有效态含量的测定,对评价和控制其生物毒害作用具有更实际的意义。镉是生物蓄积性强、具有"三致"作用的剧毒元素,会通过食物链富集到人体,从而对人体健康造成危害[2]。目前我国暂未制定土壤中有效态镉的限量标准,关于土壤中有效态镉含量测定方法的研究也较少[3-5],国家标准方法 GB/T 23739-2009(S)《土壤质量有效态铅和镉的测定原子吸收法》前处理采用振荡器低效提取,提取时间长,试剂用量大,提取液根据含量高低选用火焰原子吸收光谱仪或者石墨炉原子吸收光谱仪,操作较繁琐,无法满足批量样品快速分析的要求。文献[3-4]采用超声提取-电感耦合等离子体质谱法,前处理操作简单,但仪器成本较高,方法应用的推广有一定的局限性,且由于土壤样品基体复杂,容易堵塞雾化器导致仪器故障。