本文采用纳米Fe3O4颗粒作为磁性核心，先用四乙氧基硅烷、再用3-巯丙基三乙氧基硅烷和3-氨丙基三乙氧基硅烷修饰Fe3O4颗粒，形成表面带-NH2和-SH的Fe3O4/SiO2纳米颗粒，进一步通过-NH2的静电吸附和Au-S键的作用将金纳米颗粒组装在Fe3O4/SiO2表面，形成具有核壳结构的Fe3O4/SiO2/Au金磁纳米颗粒，并用透射电子显微镜镜（TEM）、能量色散X射线光谱仪（EDX）、紫外可见分光光度计（UV-vis）等技术对金磁纳米颗粒进行了形貌观测及性质表征。利用Fe3O4/SiO2/Au金磁纳米颗粒作为拉曼活性基底，用表面增强拉曼光谱仪对黄曲霉毒素B1（AFB1）进行直接快速检测，发现无外磁体浓缩的情况下AFB1的检测限大于10.0 μg/mL，在外磁体浓缩金磁纳米颗粒的情况下检测限降低100倍（≤0.1 μg/mL），检测线性范围0.1 μg/mL~10.0 μg/mL，检测的样品回收率为84.35%~91.98%，相对标准偏差在4.88%~9.90%之间。

To introduce -NH2 and -SH to the surface of Fe3O4/SiO2 nanoparticles, Fe3O4 nanoparticles were first modified with tetraethoxylsilane to form Fe3O4/SiO2 nanoparticles, followed by the addition of 3-thiolpropyltriethxoysilane and 3-aminopropyltriethxoysilane. Au nanoparticles were then assembled on the surface of Fe3O4/SiO2 via the electrostatic adsorption of -NH2 and the effect of the Au-S bond to produce core-shell Fe3O4/SiO2/Au gold magnetic nanoparticles. These magnetic nanoparticles were characterized by a variety of techniques such as transmission electron microscopy (TEM), energy dispersive X-ray spectrometer (EDX) and ultraviolet spectrophotometer (UV-vis). Using Fe3O4/SiO2/Au gold magnetic nanoparticles as a Raman active substrate, aflatoxin B1 (AFB1) was directly and rapidly detected by surface-enhanced Raman spectrometry. In the absence of external magnetic concentration of gold magnetic nanoparticles, the detection limit of AFB1 was higher than 10.0 μg/mL, while in the presence of external magnetic concentration, the detection limit was decreased 100-fold (≤0.1 μg/mL) with a linear detection range of 0.1~10.0 μg/mL. The recovery rate of samples was 84.35~91.98% and the relative standard deviation was 4.88~9.90%.

国家自然科学基金青年基金项目（31301483）；浙江省教育厅科研项目（Y201329221）；教育部留学回国人员科研启动基金资助项目