高度有序ZIF-8/Au纳米复合结构阵列的构筑及其表面增强拉曼光谱的应用

Construction of highly ordered ZIF⁃8/Au nanocomposite structure arrays and application of surface⁃enhanced Raman spectroscopy

采用气-液界面自组装方式制备得到有序单层聚苯乙烯(PS)微球阵列,以此为模板,采用磁控溅射沉积方法结合热处理技术获得单层六方非密排Au纳米颗粒阵列。随后采用水热法成功制得高度有序ZIF-8/Au纳米复合结构有序阵列。探究了生长机理以及反应温度、反应时间对微观形貌和光学特性的影响,进一步探究了该复合结构阵列作为表面增强拉曼散射(SERS)活性基底的灵敏度和均一性。结果表明:当水热反应温度从25℃升高至100℃时,ZIF-8纳米颗粒的数量逐步增多,同时尺寸随之增大,表面等离激元共振(SPR)峰和衍射峰均发生了红移。当水热反应时间从10 min增至60 min时,ZIF-8纳米颗粒从围绕Au纳米颗粒选择性生长到蔓延至整个材料表面。在样品表面沉积特定厚度的Ag膜后,测得4-氨基苯硫酚(4-ATP)和罗丹明6G(R6G)两种探针分子的检测极限均为10-11mol·L^(-1),4-ATP和R6G的SERS强度与分子溶液浓度呈线性关系,相关系数R2分别为0.9801和0.9844。随机选取10个不同位置测试4-ATP的SERS谱图,得到相对标准偏差(RSD)为8.86%,表明ZIF-8/Au纳米复合结构有序阵列作为SERS基底具有良好的均匀性和稳定性。

Ordered single-layer polystyrene(PS)microsphere arrays were fabricated by using the gas/liquid interface self-assembly method,and then employed as a template,single-layer hexagonal nonclose packed Au nanoparticle ar-rays were prepared by combining magnetron sputtering deposition method as well as heat treatment technology.Sub-sequently,highly ordered ZIF-8/Au composite nanostructure arrays were successfully obtained by using the hydro-thermal method.The growth mechanism of composite nanostructure arrays and the effects of reaction temperature as well as time on the microstructure and optical properties were explored.Moreover,the sensitivity and uniformity of surface-enhanced Raman scattering(SERS)signals obtained from Ag film-decorated nanostructure arrays were fur-ther investigated.The results indicated that when the hydrothermal reaction temperature increased from 25 to 100℃,the number and size of ZIF-8 nanoparticles gradually increased,and the surface plasmon resonance(SPR)and diffraction peaks both red-shifted.When the hydrothermal reaction time increased from 10 to 60 min,ZIF-8 nanoparticles appeared from selective growth around Au nanoparticles to spread throughout the material surface.After depositing a specific thickness of Ag film onto the obtained array surface,the detection limits of Raman sig-nals from both 4-aminothiophenol(4-ATP)and rhodamine 6G(R6G)probe molecules were 10-11 mol·L^(-1).The SERS peak intensity located at 1430 cm^(-1)(4-ATP)and 1355 cm^(-1)(R6G)showed a linear relationship with the concentra-tion of each molecular solution,and the correlation coefficients R2 were 0.9801 and 0.9844,respectively.The rela-tive standard deviation(RSD)was 8.86%by comparison to the peak intensity located at 1430 cm^(-1) obtained from 4-ATP molecules(10-5 mol·L^(-1))measured at 10 randomly selected positions on the arrays.It indicated that ordered ZIF-8/Au composite nanostructure arrays as SERS enhanced substrate exhibited good stability and uniformity.