Multiple enzyme layers on carbon nanotubes for electrochemical detection down to 80 DNA copies
Multiple enzyme layers on carbon nanotubes for electrochemical detection down to 80 DNA copies
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DOI：
10.1021/ac050132g
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发表时间：
2005-07-15
影响因子：
7.4
通讯作者：
Wang, J
中科院分区：
文献类型：
--
作者：
Munge, B;Liu, GD;Wang, J
在碳纳米管(CNI)模板上使用酶多层膜进行信号放大，可以产生非常灵敏的蛋白质和核酸的电化学检测。在碳纳米管载体上的静电逐层(LBL)自组装最大限度地提高了每个结合事件的酶标签比率，提供了迄今报道的最大放大系数。吸收光谱、透射电子显微镜和电化学表征证实在单个碳纳米管载体上形成了LBL酶纳米结构。酶活性随酶层数的增加而增加。新的方法被用来监测与碱性磷酸酶示踪剂相关的夹心杂交和抗体-抗原相互作用。对影响酶载量和分析性能的因素进行了优化。这种放大的生物电子分析使DNA和蛋白质的检测分别减少到80个拷贝(5.4am)和2000个蛋白质分子(67am)。鉴于新的CNT-LBL生物标记提供的巨大扩增，这种方法为超灵敏检测感染性病原体和疾病标记物提供了巨大的希望。
Signal amplification using enzyme multilayers on carbon nanotube (CNI) templates is shown to yield a remarkably sensitive electrochemical detection of proteins and nucleic acids. The electrostatic layer-by-layer (LBL) self-assembly onto CNT carriers maximizes the ratio of enzyme tags per binding event to offer the greatest amplification factor reported to date. Absorption spectroscopy, TEM, and electrochemical characterization confirm the formation of LBL enzyme nanostructures on individual CNT car-Tiers. The enzymatic activity is found to increase with the number of enzyme layers. The new protocol is illustrated for monitoring sandwich hybridization and antibody-antigen interactions in connection with alkaline phosphatase tracers. Factors affecting the enzyme loading and the analytical performance have been optimized. Such amplified bioelectronic assays allow detection of DNA and proteins down to 80 copies (5.4 aM) and 2000 protein molecules (67 aM), respectively. Given the enormous amplification afforded by the new CNT-LBL biolabel, such route offers great promise for ultrasensitive detection of infectious agents and disease markers.