State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; Department of Chemistry, Nanchang University, Nanchang 330031, China.
Department of Chemistry, Nanchang University, Nanchang 330031, China.
Biosens Bioelectron. 2015 Aug 15;70:246-53. doi: 10.1016/j.bios.2015.03.035. Epub 2015 Mar 17.
A magnetic and fluorescent nano-composite was prepared. It comprised of a core of Fe3O4 nanoparticles (NPs), a silica shell and satellitic Au nano-clusters (AuNCs) capped with bovine serum albumin (BSA). This nano-composite has many desirable properties, e.g. magnetism, red emission, high water solubility, and high resistance to photo-bleaching. On addition of the analyte, 6-mercaptopurine (6-MP) or indeed other similar thiols, AuNCs formed aggregates because the existing cross-links within the Fe3O4 NPs@SiO2 and AuNC structure were broken in favor of the gold-thiol bonds. On suitable irradiation of such aggregates, red fluorescence was emitted at 613 nm. It decreased significantly as a function of the added 6-MP concentration, and the quenching ratio (F0 - F) / F0 was related linearly to the concentration of 6-MP in the range of 0.01 to 0.5 μmol L(-1). The detection limit was 0.004 μmol L(-1) (S/N=3). The method was strongly selective for 6-MP in the presence of oxidants, phenols, heavy-metal ions, and especially bio-thiols.
一种磁性和荧光纳米复合材料被制备。它由 Fe3O4 纳米颗粒（NPs）的核心、二氧化硅壳和带有牛血清白蛋白（BSA）的卫星状 Au 纳米簇（AuNCs）组成。这种纳米复合材料具有许多理想的特性，例如磁性、红色发射、高水溶性和高抗光漂白性。加入分析物 6-巯基嘌呤（6-MP）或实际上其他类似的硫醇后，由于 Fe3O4 NPs@SiO2 和 AuNC 结构内的现有交联被打破，有利于金-硫键，AuNC 形成了聚集体。在适当的辐照下，红色荧光在 613nm 处发射。随着添加的 6-MP 浓度的增加，其显著降低，猝灭比（F0-F）/F0 与 6-MP 的浓度呈线性相关，在 0.01 至 0.5μmol L(-1)范围内。检测限为 0.004μmol L(-1)（S/N=3）。该方法对氧化剂、酚、重金属离子，特别是生物硫醇存在下的 6-MP 具有很强的选择性。
