General strategy for biodetection in high ionic strength solutions using transistor-based nanoelectronic sensors.
General strategy for biodetection in high ionic strength solutions using transistor-based nanoelectronic sensors.
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DOI：
10.1021/acs.nanolett.5b00133
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发表时间：
2015-03-11
期刊：
影响因子：
10.8
通讯作者：
Lieber CM
中科院分区：
文献类型：
--
作者：
Gao N;Zhou W;Jiang X;Hong G;Fu TM;Lieber CM
基于晶体管的纳米电子传感器能够以高灵敏度和空间分辨率进行无标记的实时化学和生物检测，尽管高离子强度溶液中的短德拜屏蔽长度使得与生理条件相关的应用变得困难。在这里，我们描述了一种新的和一般的策略，以克服这一挑战的场效应晶体管（FET）传感器，涉及到将多孔和生物分子可渗透的聚合物层上的FET传感器。该聚合物层增加了紧邻装置表面的区域中的有效筛选长度，从而能够实时检测高离子强度溶液中的生物分子。对具有额外聚乙二醇（PEG）修饰的硅纳米线（SiNW）场效应晶体管（FET）的研究表明，前列腺特异性抗原（PSA）可以在磷酸盐缓冲液（PB）浓度高达150 mM的溶液中容易地检测到，而没有PEG修饰的类似装置仅在浓度≤ 10 mM时表现出可检测信号。PSA的时间检测，在~130 mM离子强度PB中灵敏度至少为10 nM，线性响应高达最高（1000 nM）PSA检测浓度。目前的工作代表了在生理环境中生物化学传感的纳米电子检测器的一般应用的重要一步，并有望通过医学为相关的基础生物学研究的体外和体内生物传感开辟令人兴奋的机会。
Transistor-based nanoelectronic sensors are capable of label-free real-time chemical and biological detection with high sensitivity and spatial resolution, although the short Debye screening length in high ionic strength solutions has made difficult applications relevant to physiological conditions. Here, we describe a new and general strategy to overcome this challenge for field-effect transistor (FET) sensors that involves incorporating a porous and biomolecule permeable polymer layer on the FET sensor. This polymer layer increases the effective screening length in the region immediately adjacent to the device surface, and thereby enables detection of biomolecules in high ionic strength solutions in real-time. Studies of silicon nanowire (SiNW) field-effect transistors (FETs) with additional polyethylene glycol (PEG) modification show that prostate specific antigen (PSA) can be readily detected in solutions with phosphate buffer (PB) concentrations as high as 150 mM, while similar devices without PEG modification only exhibit detectable signals for concentrations ≤ 10 mM. Concentration-dependent measurements exhibited real-time detection of PSA with a sensitivity of at least 10 nM in ~130 mM ionic strength PB with linear response up to the highest (1000 nM) PSA concentrations tested. The current work represents an important step toward general application of nanoelectronic detectors for biochemical sensing in physiological environments, and is expected to open up exciting opportunities for in-vitro and in-vivo biological sensing relevant to basic biology research through medicine.