Department of Chemical and Forensic Sciences, College of Science, Botswana International University of Science and Technology, Plot 10071, Private Bag 16, Palapye, Botswana.
Braunschweig University of Technology, Institute for Condensed Matter Physics, Mendelssohnsstr. 3, 38106, Braunschweig, Germany.
Anal Chim Acta. 2019 Sep 27;1073:62-71. doi: 10.1016/j.aca.2019.04.061. Epub 2019 Apr 30.
In this study, silver nanostructures decorated magnetic nanoparticles for surface-enhanced Raman scattering (SERS) measurements were prepared via heat induced catalytic activity of ZnO nanostructures. The ZnO/FeO composite was first prepared by dispersing pre-formed magnetic nanoparticles into alkaline zinc nitrate solutions. After annealing of the precipitates, the formed ZnO/FeO composites were successfully decorated with silver nanostructures by dispersing the composites into silver nitrate/ethylene glycol solution at 95 °C in water bath. To find the optimal condition when preparing Ag/ZnO/FeO composites for SERS measurements, factors such as reaction time and concentration of silver nitrate were studied. Results indicated that the formation of silver nanoparticles (AgNPs) on ZnO/FeO was significantly improved with the assistance of ZnO. The concentration of silver nitrate and reaction time affected the morphologies and sizes of the formed composites and optimal condition in preparation of the composites for SERS measurement was found using 100 mM of silver nitrate with a reaction time of 20 min. Under optimized conditions, the obtained SERS intensities were highly reproducible. The substrates were applied for quantitative analysis of uric acid in aqueous solution and a linear response for concentrations up to 10 μM was obtained. Successful application of these prepared composites to determine uric acid in urine sample without any pretreatment of the urine sample was done.
在这项研究中，通过氧化锌纳米结构的热诱导催化活性，制备了用于表面增强拉曼散射（SERS）测量的银纳米结构修饰的磁性纳米粒子。首先通过将预先形成的磁性纳米粒子分散到碱性硝酸锌溶液中制备 ZnO/FeO 复合材料。沉淀退火后，将复合材料分散到硝酸银/乙二醇溶液中，在 95°C 的水浴中成功地在 ZnO/FeO 复合材料上修饰了银纳米结构。为了找到用于 SERS 测量的 Ag/ZnO/FeO 复合材料的最佳制备条件，研究了反应时间和硝酸银浓度等因素。结果表明，在氧化锌的辅助下，AgNPs 在 ZnO/FeO 上的形成得到了显著提高。硝酸银的浓度和反应时间影响形成的复合材料的形貌和尺寸，在制备 SERS 测量用复合材料的最佳条件下，使用 100mM 的硝酸银，反应时间为 20min。在优化条件下，获得的 SERS 强度具有高度的重现性。这些基底被应用于水溶液中尿酸的定量分析，得到了高达 10µM 的浓度的线性响应。这些制备的复合材料被成功地应用于无需尿液样品预处理即可测定尿液样品中的尿酸。
