Quantitative real-time measurements of DNA hybridization with alkylated nonoxidized silicon nanowires in electrolyte solution
Quantitative real-time measurements of DNA hybridization with alkylated nonoxidized silicon nanowires in electrolyte solution
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DOI：
10.1021/ja065923u
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发表时间：
2006-12-20
影响因子：
15
通讯作者：
Heath, James R.
中科院分区：
文献类型：
--
作者：
Bunimovich, Yuri L.;Shin, Young Shik;Heath, James R.
用硅纳米线（SiNWs）在生理相关的电解质溶液中定量、实时检测单链寡核苷酸。通过在胺端NW表面上利用静电吸附的初级DNA，避免了杂交事件的德拜筛选。比较了两种表面功能化化学性质：在SiNW的原生SiO2表面上的氨基端硅氧烷单层和直接在端氢SiNW表面上生长的氨基端烷基单层。不含天然氧化物的SiNWs表现出更好的溶液门控场效应晶体管特性，对单链DNA检测的灵敏度显著提高，同时在传感的动态范围内提高了2个数量级。建立了用SiNW传感器检测分析物的模型，并利用该模型提取dna结合动力学参数。这些数值与表面等离子体共振（SPR）的标准方法得到的数值直接比较，证明是相似的。然而，纳米线具有更高的检测灵敏度。这意味着sinw可以用于定量低浓度生物分子的溶液相浓度。这项工作也证明了表面化学对优化硅纳米线生物分子传感的重要性。
The quantitative, real-time detection of single-stranded oligonucleotides with silicon nanowires (SiNWs) in physiologically relevant electrolyte solution is demonstrated. Debye screening of the hybridization event is circumvented by utilizing electrostatically adsorbed primary DNA on an amine-terminated NW surface. Two surface functionalization chemistries are compared: an amine-terminated siloxane monolayer on the native SiO2 surface of the SiNW, and an amine-terminated alkyl monolayer grown directly on a hydrogen-terminated SiNW surface. The SiNWs without the native oxide exhibit improved solution-gated field-effect transistor characteristics and a significantly enhanced sensitivity to single-stranded DNA detection, with an accompanying 2 orders of magnitude improvement in the dynamic range of sensing. A model for the detection of analyte by SiNW sensors is developed and utilized to extract DNA-binding kinetic parameters. Those values are directly compared with values obtained by the standard method of surface plasmon resonance (SPR) and demonstrated to be similar. The nanowires, however, are characterized by higher detection sensitivity. The implication is that SiNWs can be utilized to quantitate the solution-phase concentration of biomolecules at low concentrations. This work also demonstrates the importance of surface chemistry for optimizing biomolecular sensing with silicon nanowires.