DPDAP－H_2O_2－HRP显色光度法测定HRP的研究

首次提出了Ｎ，Ｎ－二氯二甲基对苯二胺一Ｈ２Ｏ２－ＨＲＰ光度法测定ＨＲＰ的方法。ＨＲＰ催化Ｈ２Ｏ２氧化Ｎ，Ｎ－二氯二甲基对苯二胺生成有色化合物，通过测定有色化合物在λｍａｘ＝５５３．６ｎｍ处的吸光光度值，间接测定ＨＲＰ的含量。在所选定的实验条件下，ＨＲＰ的线性范围为１．０×１０－１０～１．０×１０－８ｇ／ｍＬ，本法用于游离ＨＲＰ的测定，与经典的ＥＬＩＳＡ显色光度法相比，灵敏度提高了一个数量级。ＨＲＰ的检测限为５．１×１０－１１ｇ／ｍＬ。     

从螺旋藻中提取β－胡萝卜素的研究

对以石油醚为溶剂从螺旋藻中提取β－胡萝卜素的工艺条件进行了研究。实验结果表明，最佳提取条件为：固液比１３０，提取时间５０ｍｉｎ，提取温度７０℃，且一次性提取有较高的提取率，其它色素在本实验条件下对提取β－胡萝卜素的干扰较小     

体系中的微量水对阳离子聚合的影响

通过聚合物的性质以及紫外光谱分析证明了以TiCl_4为共引发剂的阳离子聚合体系中微量水与引发剂和TiCl_4之间存在着络合竞争,并提出了抑制水对阳离子聚合影响的方法。     

Facile preparation and property analyses of L-CNC/SiO2-based composite superhydrophobic coating

In recent years, superhydrophobic coatings have received extensive attention due to their functions of waterproof, antifouling, self-cleaning, etc. However, wide applications of superhydrophobic coatings are still affected by their disadvantages of complex preparation, low mechanical properties, and poor ultraviolet (UV) resistance. In this study, cellulose nanocrystal containing a small amount of lignin (L-CNC)/SiO₂ composite particles were used as the main material, polydimethylsiloxane (PDMS) as the adhesive and perfluorooctyltrichlorosilane (FOTS) as the modifier to prepare superhydrophobic coatings by a one-step spray method. The resulted coating showed excellent superhydrophobicity (water contact angle (WCA) of 161° and slide angle (SA) of 7°) and high abrasion resistance (capable of withstanding 50 abrasion cycles under the load of 50 g). Moreover, it still maintained good superhydrophobicity after 5 h of exposure to the UV light (1000 W), displaying its good UV resistance. This study provides theoretical and technical reference for the simple preparation of organic‒inorganic composite superhydrophobic coatings with high abrasion resistance and good UV resistance, which is beneficial to improving the practicability and broadening the application scope of superhydrophobic coatings.     

Enhanced structural and optical properties of ZnO nanopowder with tailored visible luminescence as a function of sodium hydroxide to zinc sulfate mass ratio

ZnO nanopowders of tailored particle sizes were synthesized using a simple wet chemical method, by controlling the mass ratio of the precursors. The physical properties were investigated as a function of OH^?/Zn²⁺ mass ratio (x). The structural properties of the synthesized nanoparticles (NPs) are studied using X-ray diffraction (XRD). XRD patterns show pure wurtzite structure. Microstructural parameters dependence on x ratio was studied based on Williamson-Hall model. We notice an increase in crystallite size (17–24?nm) and a decrease in strain values when the x ratio increases (0.5–1.4). The best crystallinity corresponds to the higher mass ratio. Indeed, for x?=?1.4 we obtain the largest crystallite size, the lowest strain and stacking faults. The TEM images support the XRD results. Raman spectra confirm the purity of the synthesized ZnO powder. Furthermore, the optical properties were examined by UV–vis and Photoluminescence as a function of precursor’s ratio. Absorption data show a band gap red-shift of the ZnO-NPs with increase in particle’s size. Moreover, we found that the ZnO-NPs luminescence in the visible range can be engineered by changes of x ratio. This constitutes an advantage for the use of ZnO-NPs in different wavelength areas in optoelectronic applications covering UV-Blue-Green domain for the LED design, sensors…     

Plant Sunscreen and Co(II)/(III) Porphyrins for UV‐Resistant and Thermally Stable Perovskite Solar Cells: From Natural to Artificial

The poor UV, thermal, and interfacial stability of perovskite solar cells (PSCs) makes it highly challenging for their technological application, and has drawn increasing attention to resolving the above issues. In nature, plants generally sustain long exposure to UV illumination without damage, which is attributed to the presence of the organic materials acting as sunscreens. Inspired by the natural phenomenon, a natural plant sunscreen, sinapoyl malate, an ester derivative of sinapic acid, is employed to modify the surface of electron transport materials (ETMs). The interfacial modification successfully resolved the UV stability and reduced the poor interfacial contact between ETM and perovskite. The best efficiency of fabricated PSCs is up to 19.6%. Furthermore, we employed a mixture of Co(II) and Co(III)‐based porphyrin compounds containing the excellent Co(II)/Co(III) redox couple to substitute the commonly used hole transport material, 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9‐spiro‐bifluorene (spiro‐OMeTAD), to resolve the thermal degradation of PSCs noted at and above 80 °C that originates from ion diffusion of I^? and CH₃NH₃⁺ (MA⁺) ions from perovskite into spiro‐OMeTAD. Finally, the stable PSCs with the best efficiency up to 20.5% are successfully fabricated.     

新型紫外非线性光学晶体KNa5Ca5(CO3)8的合成、表征及性能的研究

采用水热法合成出一种新型碳酸盐非线性光学晶体材料KNa₅Ca₅(CO₃)₈, 该晶体属于六方晶系, 空间群为P63mc, 晶胞参数为a=b=1.00786(4) nm, c=1.26256(8) nm, Z=2。其晶体结构可以看作是由站立的[CO₃]基团连接相邻的两个[CaCO₃]_∞层, 从而沿[010]方向形成了四种不同类型的孔洞, 在这些孔洞中填充着K、Na 和[Na_0.67Ca_0.33]原子。KNa₅Ca₅(CO₃)₈晶体的粉末倍频效应为KDP的1.2倍, 且能够在可见光区实现相位匹配。紫外-可见-近红外漫反射光谱测试结果表明其晶体具有较大的光学带隙, 大概为5.95 eV, 是具有潜在应用前景的紫外非线性光学晶体材料。此外, 第一性原理的计算结果表明, 晶体的非线性系数主要来源于CO₃基团。     

A methacrylic hyaluronic acid derivative for potential application in oral treatment of celiac disease

Objective: Aim of this work was the synthesis of a methacrylic hyaluronic acid (HA) derivative and the production, via photocrosslinking, of related hydrogels loaded with an endopeptidase intended for a potential oral treatment of celiac disease.

Methods: The methacrylic derivative of HA was prepared through a one-pot procedure involving the reaction with ethylenediamine (EDA) and methacrylic anhydride (MA). The obtained derivative, named HA-EDA-MA, was used to prepare photocrosslinked hydrogels loaded with a prolyl endopeptidase derived from Flavobacterium meningosepticum (PEP FM) able to detoxify gliadin. Obtained hydrogels were recovered as gels or freeze-dried powders.

Results: Hydrogels obtained as freeze-dried powders, are able to protect loaded enzyme from degradation due to freeze-drying process and from alteration during storage, overall in the presence of a cryoprotectant. All photocrosslinked HA-EDA-MA hydrogels (gels and powders) release PEP FM in simulated intestinal fluid in sustained manner and in active form. HA-EDA-MA hydrogels are nontoxic as demonstrated through in vitro studies on BALB 3T3 cells.

Conclusions: Prepared hydrogels show a potential application for oral treatment of celiac disease thanks to the possibility to release enzymes able to detoxify the gliadin peptide that induces the immunogenic response.     

Distinguishable Detection of Ultraviolet,Visible, and Infrared Spectrum with High‐Responsivity Perovskite‐Based Flexible Photosensors

Distinguishable detection of the ultraviolet, visible, and infrared spectrum is promising and significant for the super visual system of artificial intelligences. However, it is challenging to provide a photosensor with such broad spectral response ability. In this work, the ultraviolet, visible, and infrared spectrum is distinguished by developing serial photosensors based on perovskite/carbon nanotube hybrids. Oraganolead halide perovskites (CH₃NH₃PbX₃) possess remarkable optoelectronic properties and tunable optical band gaps by changing the halogens, and integration with single‐walled carbon nanotubes can further improve their photoresponsivities. The CH₃NH₃PbCl₃‐based photosensor shows a responsivity up to 10⁵ A W^?1 to ultraviolet and no obvious response to visible light, which is superior to that of most ultraviolet sensors. The CH₃NH₃PbBr₃‐based photosensor exhibits a high responsivity to visible light. Serial devices of the two hybrid photosensors with comparable electric and sensory performances can distinguish the spectrum of ultraviolet, visible, and infrared even with varying light intensities. The photosensors also demonstrate excellent mechanical flexibility and bending stability. By taking full advantages of the oraganolead halide perovskites, this work provides flexible high‐responsivity photosensors specialized for ultraviolet, and gives a simple strategy for distinguishable detection of ultraviolet, visible, and infrared spectrum based on the serial flexible photosensors.