Liu Meichuan, Shi Guoyue, Zhang Li, Zhao Guohua, Jin Litong
Department of Chemistry, Tongji University, 1239 Siping Road, Shanghai, 200092, China.
Anal Bioanal Chem. 2008 Jul;391(5):1951-9. doi: 10.1007/s00216-008-2103-z. Epub 2008 Apr 16.
Three-dimensionally structured, silica based, organic-inorganic hybrid nanoparticles (NPs) were prepared by a simple and feasible water-in-oil (W/O) microemulsion method and a promising platform for bioelectrochemical analysis was obtained. The commonly used phenathiazine organic compound, toluidine blue (TB) was readily captured in the three-dimensional cage of the inorganic SiO(2) network, which was considered to serve as a protective "shell" toward the embedded TB. A TEM image indicated the size of the thus prepared TB-doped SiO(2) (TB@SiO(2)) NPs was 21 +/- 3 nm. UV-visible and IR spectroscopy confirmed successful formation of the organic-inorganic composite and possible interaction between TB and SiO(2), which favored enhanced stability of the hybrid. A sensitive amperometric sensor for hemoglobin (Hb) biomolecules based on TB@SiO(2) NPs conjugated with a biopolymer chitosan (CHIT) membrane was then developed. The surface of the silica NPs was highly biocompatible and the TB captured inside maintained its high electron-transfer efficiency. Dye leakage of TB from the TB@SiO(2) hybrid was proved to be minimal, owing to the inorganic SiO(2) network and the force of interaction between TB and SiO(2). The amperometric sensor had a detection limit of 2.5 x 10(-9) mol L(-1) (S/N = 3) with a linear range from 5.0 x 10(-9) to 3.0 x 10(-6) mol L(-1) for Hb. When it was applied to determine the concentration of a clinical blood sample, satisfactory results were obtained which were in good agreement with those obtained by the standard method.
通过一种简单可行的油包水（W/O）微乳液法制备了三维结构的、基于二氧化硅的有机-无机杂化纳米粒子（NPs），并获得了一个用于生物电化学分析的有前景的平台。常用的吩噻嗪有机化合物甲苯胺蓝（TB）很容易被捕获在无机SiO₂网络的三维笼状结构中，该无机SiO₂网络被认为对嵌入的TB起到保护“壳”的作用。透射电子显微镜（TEM）图像表明，如此制备的TB掺杂的SiO₂（TB@SiO₂）纳米粒子的尺寸为21±3nm。紫外可见光谱和红外光谱证实了有机-无机复合材料的成功形成以及TB与SiO₂之间可能的相互作用，这有利于提高杂化物的稳定性。然后开发了一种基于与生物聚合物壳聚糖（CHIT）膜共轭的TB@SiO₂纳米粒子的用于血红蛋白（Hb）生物分子的灵敏安培传感器。二氧化硅纳米粒子的表面具有高度生物相容性，捕获在内部的TB保持其高电子转移效率。由于无机SiO₂网络以及TB与SiO₂之间的相互作用力，证明TB从TB@SiO₂杂化物中的染料泄漏极少。该安培传感器对Hb的检测限为2.5×10⁻⁹mol L⁻¹（S/N = 3），线性范围为5.0×10⁻⁹至3.0×10⁻⁶mol L⁻¹。当将其应用于测定临床血液样本的浓度时，获得了令人满意的结果，这些结果与通过标准方法获得的结果高度一致。
