Towards a label-free optical porous silicon DNA sensor
Towards a label-free optical porous silicon DNA sensor
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DOI：
10.1016/j.bios.2004.12.008
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发表时间：
2005-10-15
影响因子：
12.6
通讯作者：
Chiavarini, S
中科院分区：
文献类型：
--
作者：
Di Francia, G;La Ferrara, V;Chiavarini, S
我们报道了一种基于硅的光学无标记DNA传感器的制作。n型晶体硅晶片已被电化学蚀刻，以形成多孔硅层，其特征在于在孔隙率，孔分布，表面组成和光致发光。切割样品（0.25 cm（2）），并使用三甲氧基-3-溴乙酰氨基丙基硅烷进行适当衍生，以连接单链DNA（ss-DNA）。这样的分子不是可商购的，并且已经通过氢溴酸和3-氨基丙基三甲氧基硅烷在作为偶联剂的1-（3-二甲基氨基丙基）-3-乙基碳二亚胺的存在下反应特别制备。三甲氧基-3-溴乙酰氨基丙基硅烷作为一个桥梁锚定的多孔硅表面通过硅烷基团，同时固定ss-DNA的溴乙酰氨基部分的装置。我们已经发现，衍生化的样品表现出随时间稳定的光致发光，并且在暴露于非互补DNA链后不被改变。另一方面，当衍生化的样品与互补链反应时，已经观察到光发射的明显增强，表明特异性ss-DNA/互补DNA（c-DNA）相互作用可以在不使用进一步标记步骤的情况下被光学感测。这有力地加强了硅作为生物传感器材料的可能作用。(c)2004 Elsevier B. V.保留所有权利。
We report on the fabrication of an optical silicon-based label-free DNA sensor. n-Type crystalline silicon wafers have been electrochemically etched to form porous silicon layers and characterized in terms of porosity, pore distribution, surface composition and photoluminescence. Samples (0.25cm(2)) have been cut and properly derivatized using trimethoxy-3-bromoacetamidopropylsilane in order to link single strand DNA (ss-DNA). Such a molecule is not commercially available and has been ad-hoc prepared by reacting hydrobromic acid and 3-aminopropyltrimethoxysilane in presence of 1-(3-diinethylaminopropyl)-3-ethylcarbodiimide as coupling agent. Trimethoxy-3bromoacetamidopropylsilane acts as a bridge anchored to the porous silicon surface through the silane group while immobilizing ss-DNA by means of the bromoacetamido moiety. We have found that derivatized samples exhibit a photoluminescence that is stable in time and is not modified after exposure to non-complementary DNA strand. On the other hand, a sensible enhancement of the light emission has been observed when the derivatized samples react with the complementary strand, showing that the specific ss-DNA/complementary DNA (c-DNA) interaction can be optically sensed without using further labeling steps. This strongly strengthens the possible role of silicon as a material for biosensors. (c) 2004 Elsevier B.V. All rights reserved.