Although DNA recognition has been achieved using numerous biosensors with various sensing probes, the utilization of bio-interaction between DNA and biomolecules has seldom been reported in universal DNA detection. Peptides as natural molecules have the unique ability to bind to universal DNA and excellent selectivity for DNA after being functionalized with specific groups. In this work, we report a peptide based carbon nanotube (CNT) thin-film-transistor (TFT) biosensor, which can achieve sensitive sequence-independent DNA detection. In the presence of DNA, a significant increase of ΔIon could be observed within 5 minutes, which was considered to be due to the electrostatic adsorption between the DNA and peptide of opposite zeta potential. With the gradual increase of the concentration of DNA, the ΔIon signals agree with the Hill–Langmuir model (R² = 0.98), indicating a negatively cooperative interaction between the peptide and DNA (the Hill coefficient n < 1). Compared with the former reported universal DNA bio-detector and NanoDrop (a spectrometer from Thermo Scientific™), this unique peptide based CNT-DNA sensor demonstrated a broader sensing range from nearly 1.6 × 10⁻⁴ to 5 μmol L⁻¹ and a much lower detection limit of approximately 0.88 μg L⁻¹. For the quantification of cDNA from T47D cancer cells, this unique peptide based CNT sensor could achieve efficient cDNA detection. To the best of our knowledge, this is the first report on the utilization of a peptide as a sensing element in the design of CNT based DNA biosensors, which enables highly efficient universal DNA detection.

中文翻译：

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基于肽的碳纳米管生物传感器实现通用 DNA 检测

尽管已经使用具有各种传感探针的众多生物传感器实现了 DNA 识别，但在通用 DNA 检测中很少报道利用 DNA 和生物分子之间的生物相互作用。肽作为天然分子，具有独特的与通用 DNA 结合的能力，在被特定基团功能化后对 DNA 具有优异的选择性。在这项工作中，我们报告了一种基于肽的碳纳米管 (CNT) 薄膜晶体管 (TFT) 生物传感器，它可以实现灵敏的序列无关 DNA 检测。在DNA存在的情况下，5分钟内可以观察到ΔIon的显着增加，这被认为是由于DNA与相反zeta电位的肽之间的静电吸附所致。随着 DNA 浓度的逐渐增加，ΔIon 信号与 Hill-Langmuir 模型一致（R ² = 0.98），表明肽和 DNA 之间存在负协同作用（希尔系数n < 1）。与之前报道的通用 DNA 生物检测器和 NanoDrop（来自 Thermo Scientific™ 的光谱仪）相比，这种独特的基于肽的 CNT-DNA 传感器表现出从近 1.6 × 10 ^-4到 5 μmol L ^-1的更宽的传感范围和远检测下限约为 0.88 μg L ^-1. 对于来自 T47D 癌细胞的 cDNA 定量，这种独特的基于肽的 CNT 传感器可以实现高效的 cDNA 检测。据我们所知，这是第一份关于在基于 CNT 的 DNA 生物传感器设计中使用肽作为传感元件的报告，该传感器能够实现高效的通用 DNA 检测。