金磁纳米颗粒的制备及其在表面增强拉曼光谱快速检测黄曲霉毒素B1中的应用

Fabrication of Gold Magnetic Nanoparticles and Their Application for Rapid Detection of Aflatoxin B_1 Using Surface-enhanced Raman Spectroscopy

本文采用纳米Fe_3O_4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Fe_3O_4颗粒,形成表面带-NH_2和-SH的Fe_3O_4/SiO_2纳米颗粒,进一步通过-NH_2的静电吸附和Au-S键的作用将金纳米颗粒组装在Fe_3O_4/SiO_2表面,形成具有核壳结构的Fe_3O_4/SiO_2/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Fe_3O_4/SiO_2/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10.0μg/m L,在外磁体浓缩金磁纳米颗粒的情况下检测限降低100倍(≤0.1μg/m L),检测线性范围0.1μg/m L^10.0μg/m L,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-NH_2 and-SH to the surface of Fe_3O_4/SiO_2 nanoparticles, Fe_3O_4 nanoparticles were first modified with tetraethoxylsilane to form Fe_3O_4/SiO_2 nanoparticles, followed by the addition of 3-thiolpropyltriethxoysilane and 3-aminopropyltriethxoysilane. Au nanoparticles were then assembled on the surface of Fe_3O_4/SiO_2 via the electrostatic adsorption of-NH_2 and the effect of the Au-S bond to produce core-shell Fe_3O_4/SiO_2/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 Fe_3O_4/SiO_2/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/m L, while in the presence of external magnetic concentration, the detection limit was decreased 100-fold（≤0.1 μg/m L） with a linear detection range of 0.1~10.0 μg/m L. The recovery rate of samples was 84.35~91.98% and the relative standard deviation was 4.88~9.90%.