Ultrasensitive in Situ Label-Free DNA Detection Using a GaN Nanowire-Based Extended-Gate Field-Effect-Transistor Sensor
Ultrasensitive in Situ Label-Free DNA Detection Using a GaN Nanowire-Based Extended-Gate Field-Effect-Transistor Sensor
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DOI：
10.1021/ac102489y
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发表时间：
2011-03-15
影响因子：
7.4
通讯作者：
Chen, Li-Chyong
中科院分区：
文献类型：
--
作者：
Chen, Chin-Pei;Ganguly, Abhijit;Chen, Li-Chyong
在这项研究中，我们成功地证明了基于GaN纳米线(GaNNW)的扩展栅场效应管(EGFET)生物传感器能够在无标记的原位条件下识别特定的DNA序列。我们的方法显示了GaN的宽禁带半导体特性、NW结构的表面敏感性和EGFET设计的高转换性能的良好集成。这种简单的传感器结构，通过将合成的GaNNW与商用FET器件直接组装，可以实现低于大摩尔浓度的超高检测极限：分辨率比其他基于FET的DNA传感器高约3个数量级。对错配(与人类P53肿瘤抑制基因相关的热点突变)和互补靶标的原位比较研究显示，即使在存在非互补DNA链的情况下，该传感器也具有良好的选择性和特异性，这表明该传感器在复杂的临床样本中具有潜在的实用应用价值。与GaN薄膜相比，NW基EGFET具有优良的性能，在10(-19)-10(-6)M的探测范围内，灵敏度提高了约2个数量级，检测下限达到了约6个数量级。研究表明了纳米材料的独特和独特的特征。详细的研究表明，生物材料-半导体杂化界面的能带排列对系统的有效电容和载流子迁移率有积极的影响。
In this study, we have successfully demonstrated that a GaN nanowire (GaNNW) based extended-gate field-effect-transistor (EGFET) biosensor is capable of specific DNA sequence identification under label-free in situ conditions. Our approach shows excellent integration of the wide bandgap semiconducting nature of GaN, surface-sensitivity of the NW-structure, and high transducing performance of the EGFET-design. The simple sensor architecture, by direct assembly of as synthesized GaNNWs with a commercial FET device, can achieve an ultrahigh detection limit below attomolar level concentrations: about 3 orders of magnitude higher in resolution than that of other FET-based DNA-sensors. Comparative in situ studies on mismatches ("hotspot" mutations related to human p53 tumor-suppressor gene) and complementary targets reveal excellent selectivity and specificity of the sensor, even in the presence of noncomplementary DNA strands, suggesting the potential pragmatic application in complex clinical samples. In comparison with GaN thin film, NW-based EGFET exhibits excellent performance with about 2 orders higher sensitivity, over a detection range, 10(-19)-10(-6) M, reaching about a 6-orders lower detection limit. Investigations illustrate the unique and distinguished feature of nanomaterials. Detailed studies indicate a positive effect of energy band alignment at the biomaterials-semiconductor hybrid interface influencing the effective capacitance and carrier-mobility of the system.