氮掺杂石墨烯量子点/细菌纤维素复合膜的制备及应用

以一水合柠檬酸和尿素为前驱体,采用一步水热法制备出具有良好水溶性和荧光性能的氮掺杂石墨烯量子点(N-GQDs)。以细菌纤维素(BC)为基体,采用原位浸渍的方法制备出了N-GQDs/BC复合膜。通过紫外-可见光谱仪、X射线衍射仪、傅里叶变换红外光谱仪、荧光光谱仪、透射电子显微镜对N-GQDs的结构和性能进行了表征,开发出一种绿色简单的荧光生物传感器并用于多巴胺(DA)的敏感检测。结果表明:N-GQDs/BC复合膜的荧光强度能有效地被DA猝灭,且DA浓度在0~100μmol/L的范围内呈现出很好的线性关系,检测限为3.3×10~(-8)mol/L;通过分析淬灭机制证明了荧光猝灭是由于电子转移导致的。     

贻贝仿生涂层修饰聚合物微球固定化脂肪酶的制备及应用

为构建新型固定化酶催化体系,以聚甲基丙烯酸缩水甘油酯为载体,利用贻贝仿生技术——多巴胺/聚乙烯亚胺共沉积进行修饰,采用扫描电镜（SEM）、能谱（EDS）、Zeta电位及红外光谱（FT-IR）表征所得材料,并研究其固定化近平滑假丝酵母CICC 33470所产脂肪酶的表征及酶学性质。最佳酶固定化条件为：固定化温度为30 ℃,固定化pH为7.0,固定化时间为5 h,初始酶活为337.76 U/mL,载体添加量为0.2 g。固定化酶最佳反应温度为50 ℃,最佳反应pH为8.0,最佳反应时间为10 min,最优条件下固定化酶酶活为484.42±5.97 U/g-载体。固定化酶的稳定性明显提高,重复使用8次后,固定化酶仍有39.22%的初始酶活。进一步将固定化酶用于催化乙酰丙酸与十二醇的酯化反应,转化率可达75.94%,充分证明聚甲基丙烯酸缩水甘油酯经修饰后是固定化脂肪酶的优良载体,为未来扩大脂肪酶的应用范围提供了基础数据。     

基于多巴胺及其衍生物的传感器在食品快速检测中的研究进展

食品安全问题关系国计民生,快速检测技术对实现食品安全战略具有重要意义.聚多巴胺及其复合材料修饰的传感器在食品快速检测中表现出良好的稳定性,且具有检测限低、灵敏度高的优势;此外,聚多巴胺及其修饰复合材料制备过程简单、绿色环保,基于这些优点,聚多巴胺及其复合材料在食品安全评价、环境监测、生物分析等领域的运用备受关注.本文综...     

掺硼金刚石薄膜电极的氨基化改性及电化学行为

采用重氮盐电化学还原的方法对掺硼金刚石薄膜电极进行氨基化改性,光电子能谱（XPS）证明表面N元素的存在,同时可以通过406 eV、400 eV峰强度的变化,证明硝基还原为氨基。以Fe(CN)₆^－3/－4氧化还原电对为探针,进一步证明了氨基层的存在。采用循环伏安法和差分脉冲伏安法研究了改性后电极的电化学行为。通过分别检测多巴胺和抗坏血酸以及它们的混合溶液,表明选用差分脉冲伏安法,氨基化改性掺硼金刚石薄膜电极能够有效分离检测两者的氧化峰,分离后两峰电势差约为0.3 V。电极表面吸附血浆蛋白后,阻碍了Fe(CN)₆^－3/－4氧化还原对的电子传递,但是并不妨碍多巴胺的检测。     

液质法测定动物源性食品中肾上腺素、多巴胺

为同时测定动物源性食品中肾上腺素、多巴胺的含量,建立HPLC-MS-MS检测方法。该两种物质的线性范围均为3～1500μg/kg。低、中、高三种浓度加标回收率均为90%～101%;检出限分别为肾上腺素1μg/kg、多巴胺3μg/kg。本方法快速简便,灵敏度高,选择性好,测定结果令人满意,可在各食品检测机构推广应用。     

苯酰胺类D2受体新配体的合成,125I标记及生物分布研究

合成了苯酰胺类D2受体配体（S）－N－[(1-羟乙基－2－四氢吡咯烷基）甲基]－50氨基－2,3－二甲氧基苯甲胺胺（HEABZM）,用红外光谱,核磁共振和质谱法进行了表征。以HEABZM为标记前体,制备了（S）－N－[1－羟乙基－2－四氢吡咯烷基）甲基]－5－氨基－4－^125I,3－二甲苯甲酰胺。标记率为79％,经萃取分离后,放化纯度在90％以上。小鼠休丙初步生物分布研究表明,该配合物在小鼠脑中有一定的区域分布,纹状体与小脑的比值略大于1。     

Selective Pharmacophore Models of Dopamine D1 and D2 Full Agonists Based on Extended Pharmacophore Features

This study is focused on the identification of structural features that determine the selectivity of dopamine receptor agonists toward D₁ and D₂ receptors. Selective pharmacophore models were developed for both receptors. The models were built by using projected pharmacophoric features that represent the main agonist interaction sites in the receptor (the Ser residues in TM5 and the Asp in TM3), a directional aromatic feature in the ligand, a feature with large positional tolerance representing the positively charged nitrogen in the ligand, and sets of excluded volumes reflecting the shapes of the receptors. The sets of D₁ and D₂ ligands used for modeling were carefully selected from published sources and consist of structurally diverse, conformationally rigid full agonists as active ligands together with structurally related inactives. The robustness of the models in discriminating actives from inactives was tested against four ensembles of conformations generated by using different established methods and different force fields. The reasons for the selectivity can be attributed to both geometrical differences in the arrangement of the features, e.g., different tilt angels of the π system, as well as shape differences covered by the different sets of excluded volumes. This work provides useful information for the design of new D₁ and D₂ agonists and also for comparative homology modeling of D₁ and D₂ receptors. The approach is general and could therefore be applied to other ligand–protein interactions for which no experimental protein structure is available.