排序方式: 共有23条查询结果,搜索用时 453 毫秒
21.
22.
Rodrigo Vieira Blasques Wilson S. Fernandes-Junior Ana Márcia Rabelo Vieira Mendes Andressa Rose Castro Costa Thiago C. Canevari Leliz Ticona Arenas Marcelo Barcellos da Rosa Gilvanda Silva Nunes Bruno Campos Janegitz Maria Raimunda Chagas Silva María Isabel Pividori Paulo Cesar Mendes Villis 《Electroanalysis》2023,35(5):e202200373
In this work, we have proposed an electrochemical sensor for the detection of pesticides by using a ceramic composite with a SiO2 surface modified with Sm2O3 nanoparticles and C-graphite (SSMG), obtained by the sol-gel process and immobilized by adsorption in Meldola Blue cationic dye (MB). The composite was called (SSMG/MB), which was characterized by spectroscopic, electrochemical techniques, Fourier-transform infrared spectroscopy, and Cyclic Voltammetry. The proposed sensor was applied for the glyphosate electrochemical detection, using Differential Pulse Voltammetry, and, under optimized parameters has presented the linear response for the pesticide in the concentration range from 0.99 to 7.94 (μmol L−1; R2=0.9963; n=8). The calculated values for the detection limit and the quantification limit were 0.15 and 0.49 μmol L−1, respectively. Therefore, the new electrochemical sensor based on SiO2, NPsSm2O3, C-graphite, and MB hybrid material was developed for the first time for glyphosate determination, which has demonstrated high potential for the development of new hybrid devices for environmental control. 相似文献
23.
Andréia de Morais Gustavo Silveira Paulo César Mendes Villis Camila Marchetti Maroneze Yoshitaka Gushikem Fábio Luiz Pissetti Alzira Maria Serpa Lucho 《Journal of Solid State Electrochemistry》2012,16(9):2957-2966
A simple preparation methodology able to stabilize gold nanoparticles and to obtain an electrode which detects ascorbic acid, uric acid, and dopamine by different techniques is presented. A 3-mercaptopropyl-functionalized silica network was synthesized using the sol–gel method. Gold nanoparticles (nAu) were immobilized on the material at synthesis by adding a sol of these previously prepared particles to the reaction mixture. The electrochemical behavior of the SiO2/MPTS/Au carbon paste electrode was studied using cyclic voltammetry in the presence of a hexacyanoferrate probe molecule. The presence of nAu in the functionalized silica network changes the electrochemical characteristics of the material, favoring the electron transfer process of this complex ion. The SiO2/MPTS/Au electrode was proven to be an efficient tool in the simultaneous determination of ascorbic acid (H2AA), dopamine (DA), and uric acid (UA) using square wave voltammetry techniques. With the nAu on the electrode, an increase in the peak current related to the redox process of the H2AA, DA, and UA was observed. The separations of the anodic peak potentials between DA/H2AA and UA/H2AA were 310 and 442?mV, respectively. The results obtained show that the SiO2/MPTS/Au electrode can be used in the simultaneous determination of H2AA, DA, and UA. 相似文献