Silanization of Ag-Deposited Magnetite Particles: An Efficient Route to Fabricate Magnetic Nanoparticle-Based Raman Barcode Materials
Silanization of Ag-Deposited Magnetite Particles: An Efficient Route to Fabricate Magnetic Nanoparticle-Based Raman Barcode Materials
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DOI：
10.1021/am1002074
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发表时间：
2010-07-01
影响因子：
9.5
通讯作者：
Shin, Kuan Soo
中科院分区：
文献类型：
--
作者：
Kim, Kwan;Choi, Jeong-Yong;Shin, Kuan Soo
开发了可用作基于磁性纳米颗粒的拉曼条形码材料的二氧化硅涂覆的银纳米结构。首先，合成了由13 nm大小的超顺磁性Fe 3 O 4纳米颗粒组成的283 nm大小的球形磁铁矿颗粒，并使用丁胺作为AgNO 3在乙醇中的还原剂进行银沉积。Ag沉积的Fe 3 O 4（Fe3O4@Ag）颗粒被发现是有效的表面增强拉曼散射（Sers）基底，在632.8 nm激发下的增强因子约为3 × 10（6）。Sers标记物，如苯乙烷，4-巯基甲苯，4-氨基苯乙烷，和4-硝基苯乙烷吸附到银表面上后，聚（烯丙基胺盐酸盐）（PAH）被涂覆到它们上使用逐层沉积方法，使得随后的碱催化硅烷化可以很容易地形成一个60 nm厚的二氧化硅壳层周围的PAN层的仿生过程。交联的二氧化硅壳有效地防止SERS标记分子从Fe3O4@Ag颗粒的表面释放。尽管由于涂覆有银和二氧化硅，克磁化强度降低到初始值的近一半，但是剩余的磁化强度仍然足够强，使得二氧化硅涂覆的Fe3O4@Ag颗粒用作通过Sers操作的条形码材料。
Silica-coated Ag nanostructures usable as magnetic nanoparticle-based Raman barcode materials were developed. Initially, 283 nm sized spherical magnetite particles composed of 13 nm sized superparamagnetic Fe3O4 nanoparticles were synthesized, and silver deposition was conducted using butylamine as the reductant of AgNO3 in ethanol. The Ag-deposited Fe3O4 (Fe3O4@Ag) particles are found to be efficient surface-enhanced Raman scattering (SERS) substrates with the enhancement factor at 632.8 nm excitation to be about 3 x 10(6). After SERS markers such as benzenethiol, 4-mercaptotoluene, 4-aminobenzenethiol, and 4-nitrobenzenethiol were adsorbed onto the silver surface, poly(allylamine hydrochloride) (PAH) was coated onto them using the layer-by-layer deposition method such that a subsequent base-catalyzed silanization could readily form a 60 nm thick silica shell around the PAN layer by a biomimetic process. The cross linked silica shells effectively prevented the SERS-marker molecules from being liberated from the surface of the Fe3O4@Ag particles. Although the gram magnetization decreased nearly to one-half, of the initial value because of coating with silver and silica, the remaining magnetization was nonetheless strong enough for the silica coated Fe3O4@Ag particles to be used as barcode materials operating via SERS.