Physique de la Matière Condensée, Ecole Polytechnique, CNRS, 91128 Palaiseau, France.
Bioelectrochemistry. 2010 Nov;80(1):17-25. doi: 10.1016/j.bioelechem.2010.03.011. Epub 2010 Apr 11.
(111) silicon surfaces can be controlled down to atomic level and offer a remarkable starting point for elaborating nanostructures. Hydrogenated surfaces are obtained by oxide dissolution in hydrofluoric acid or ammonium fluoride solution. Organic species are grafted onto the hydrogenated surface by a hydrosilylation reaction, providing a robust covalent Si-C bonding. Finally, probe molecules can be anchored to the organic end group, paving the way to the elaboration of sensors. Fluorescence detection is hampered by the high refractive index of silicon. However, improved sensitivity is obtained by replacing the bulk silicon substrate by a thin layer of amorphous silicon deposited on a reflector. The development of a novel hybrid SPR interface by the deposition of an amorphous silicon-carbon alloy is also presented. Such an interface allows the subsequent linking of stable organic monolayers through Si-C bonds for a plasmonic detection. On the other hand, the semiconducting properties of silicon can be used to implement field-effect label-free detection. However, the electrostatic interaction between adsorbed species may lead to a spreading of the adsorption isotherms, which should not be overlooked in practical operating conditions of the sensor. Atomically flat silicon surfaces may allow for measuring recognition interactions with local-probe microscopy.
(111)硅表面可以精确控制到原子级，为精细结构的阐述提供了一个极好的起点。氢化表面是通过在氢氟酸或氟化铵溶液中溶解氧化物而获得的。有机物质通过硅氢化反应接枝到氢化表面上，提供了牢固的 Si-C 键合。最后，可以将探针分子锚定到有机端基上，为传感器的研制铺平了道路。荧光检测受到硅高折射率的阻碍。然而，通过用沉积在反射器上的薄非晶硅层代替体硅衬底，可以获得更高的灵敏度。还提出了通过沉积非晶硅-碳合金来开发新型混合 SPR 界面。这种界面允许通过 Si-C 键随后连接稳定的有机单层，用于等离子体检测。另一方面，硅的半导体性质可用于实现场效应无标记检测。然而，吸附物质之间的静电相互作用可能导致吸附等温线的扩展，在传感器的实际工作条件下不应忽视这种扩展。原子级平坦的硅表面可能允许通过局部探针显微镜测量识别相互作用。
