排序方式: 共有17条查询结果,搜索用时 31 毫秒
1.
2.
以木质素磺酸钠为碳源,水热法合成了MoS2掺杂的碳纳米酶(Mo, S-CDs),并基于其过氧化物酶特性,将其用于检测人尿中多巴胺的含量。对纳米酶的形貌进行了表征。结果显示,Mo, S-CDs为球型,直径在2 nm左右,在水中能够较好的分散;红外图谱结果表明Mo, S-CDs表面官能团丰富;X射线光电子能谱表明Mo, S-CDs中存在Mo, S, C, O元素。Mo, S-CDs具有稳定、高效的过氧化物酶催化活性,可催化H2O2与3,3’,5,5’-四甲基联苯胺(TMB)反应,生成氧化产物oxTMB。蓝色的oxTMB可被多巴胺还原回TMB,导致系统在oxTMB特征峰处的吸光度下降。因此,基于Mo, S-CDs对H2O2的传感能力构建了多巴胺-Mo, S-CDs的催化传感体系,并用于检测人尿液中多巴胺的含量。多巴胺浓度在0.5~20μmol/L范围内有良好的线性关系,检出限为0.0639μmol/L,回收率为96.5%~101.7%,相对标准偏差(RSD)<5%。 相似文献
3.
应用介孔分子印迹聚合物萃取粮食中的乙酰甲胺磷 总被引:1,自引:0,他引:1
以乙酰甲胺磷为模板分子,3-氨基丙基三乙氧基硅烷(APTES)为功能单体,表面活性剂正十二烷胺(DDA)为介孔模板剂,正硅酸乙酯为交联剂,采用溶胶凝胶技术制备乙酰甲胺磷介孔分子印迹聚合物(MIP),并对其进行了表征。Scatchard分析表明,该聚合物对乙酰甲胺磷有两种结合方式,最大表观结合量Q_(max1)=47.03 mg/g,Q_(max2)=90.31 mg/g;平衡解离常数k_(d1)=57.14 mg/L,k_(d2)=188.68 mg/L。吸附动力学测定结果显示,其对乙酰甲胺磷的吸附符合准二级动力学模型;吸附热力学测定结果显示其吸附为放热过程。将该聚合物用于基质固相分散萃取(MSPD)粮食中乙酰甲胺磷,最佳条件为:聚合物与样品的质量比为1∶1,研磨时间为8 min,淋洗剂为乙醇-水(2∶1,体积比),洗脱剂为乙腈-乙酸溶液(19∶1,体积比)。所得洗脱液采用高效液相色谱法检测,测得乙酰甲胺磷的线性范围为0.03~0.3μg/g,检出限为0.015μg/g,回收率为92.5%~97.1%,相对标准偏差为2.9%~3.7%。该方法兼具介孔分子印迹技术的高选择性如和MSPD技术的快速分离性,为乙酰甲胺磷残留分析提供了新思路。 相似文献
4.
该文采用Pickering双乳液法,以硝磺草酮为模板分子、甲基丙烯酸甲酯为功能单体、木质素为稳定粒子制备分子印迹聚合物,并对其进行傅里叶红外光谱、扫描电镜、X射线衍射与接触角表征,同时探究了该聚合物对硝磺草酮的静态吸附、动态吸附和选择性吸附。Scatchard分析表明:合成的聚合物对硝磺草酮的结合方式有两种,最大表观吸附量(Qmax)和平衡离解常数(Kd)分别为Qmax1 = 32.31 mg/g,Kd1 = 116.28 mg/L;Qmax2 = 89.99 mg/g,Kd2 = 413.22 mg/L。动力学测定结果显示:该聚合物对硝磺草酮的吸附符合准二级动力学模型。将制备得到的分子印迹聚合物作为基质固相分散的分散剂萃取分离玉米中的硝磺草酮。最佳萃取条件为分子印迹聚合物与样品的质量比3∶2;研磨时间10 min,淋洗剂2 mL 20%甲醇水溶液,洗脱剂5 mL 5%乙酸乙腈。最佳条件下,硝磺草酮的检出限为0.018 μg/g,回收率为97.0%~98.4%,相对标准偏差(RSD)为0.70%~5.6%。该研究分析时间短、有机溶剂用量少,且提高了选择性和分析效率。 相似文献
5.
Nitrogen-doped carbon dots (N-CDs) were prepared by one-step hydrothermal synthesis with pomegranate seeds as the carbon source and urea as the nitrogen source. Observed by transmission electron microscopy (TEM), average particle size of N-CDs was 20 nm. Observed by atomic force microscopy (AFM), the thickness of N-CDs was 0. 6-1. 4 nm. Fourier transform infra-red (FT-IR) confirmed the presence of water-soluble functional groups such as amino groups on the surface of N-CDs. With the prepared N-CDs as the target fluorophore, Hg2 + can efficiently bind to the surface of N-CDs to form a complex, and achieve static quenching. The addition of tiopronin can bind the Hg2 + in the complex to make the Hg2 + detach from the surface of N-CDs and realize fluorescence recovery. The nano fluorescence switch constructed in this work is more accurate and sensitive than the traditional detection method. The optimum conditions were determined by optimizing the pH value, reaction time, the dosage of N-CDs and Hg2 +. The relative deviation (RSD) was 4. 7%, and the detection limit was 0. 2 μmol/L. The method was used to determine the content of tiopronin in human serum samples with the recoveries of 97. 2%-101. 3%. © 2022, Youke Publishing Co.,Ltd. All rights reserved. 相似文献
6.
7.
8.