Beijing Bioprocess Key Laboratory, Beijing University of Chemical Technology, Beijing 100029, China; College of Mathematics & Physics, Beijing University of Chemical Technology, Beijing 100029, China.
Beijing Bioprocess Key Laboratory, Beijing University of Chemical Technology, Beijing 100029, China; College of Mathematics & Physics, Beijing University of Chemical Technology, Beijing 100029, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 Nov 5;241:118532. doi: 10.1016/j.saa.2020.118532. Epub 2020 May 26.
A facile method for synthesizing Au nanoparticle-coated FeO magnetic composite nanospheres (FeO@Au MCS) via seed-mediated growth and iterative reduction is reported. The nanospheres were then successfully used to detect malachite green (MG) residues in water bodies via surface-enhanced Raman scattering (SERS) technique. FeO@Au MCS has excellent optical properties and superparamagnetism; it can be dispersed into the solution to fully adsorb target molecules and then collected with a magnet to increase the molecular density and the number of SERS hot spots. Magnetic enrichment was superior to conventional detection method. The limit of detection for MG was 10 M and the enhancement factor was 1.1 × 10. The logarithm of the SERS intensity of the characteristic peak at 1618 cm exhibited a linear relationship with the logarithm of the MG concentration over the range of 10- 10 M, with a correlation coefficient of 0.966. The FeO@Au MCS had good uniformity of SERS signals, with a 18.59% relative standard deviation for the SERS intensity. MG detection in aquaculture water conformed with the established quantitative regulations. The SERS spectrum calculated with density function theory for MG adsorbed on FeO@Au MCS was very close to the experimental spectrum, which verified enhancement by the substrate. Overall, FeO@Au MCS enabled ultrasensitive, quantitative SERS detection of MG.
一种通过种子介导生长和迭代还原合成金纳米粒子包覆的 FeO 磁性复合纳米球 (FeO@Au MCS) 的简便方法被报道。然后，通过表面增强拉曼散射 (SERS) 技术，成功地将这些纳米球用于水体中孔雀石绿 (MG) 残留的检测。FeO@Au MCS 具有优异的光学性质和超顺磁性；它可以分散到溶液中，以充分吸附目标分子，然后用磁铁收集，以增加分子密度和 SERS 热点数量。磁富集优于传统检测方法。MG 的检测限为 10 M，增强因子为 1.1×10。特征峰在 1618 cm 处的 SERS 强度的对数与 MG 浓度在 10-10 M 范围内的对数呈线性关系，相关系数为 0.966。FeO@Au MCS 的 SERS 信号具有良好的均匀性，SERS 强度的相对标准偏差为 18.59%。养殖水中 MG 的检测符合既定的定量规定。用密度泛函理论计算的吸附在 FeO@Au MCS 上的 MG 的 SERS 光谱与实验光谱非常吻合，这验证了基底的增强作用。总的来说，FeO@Au MCS 实现了对 MG 的超灵敏、定量的 SERS 检测。
