College of Food Science and Technology, Henan Key Laboratory of Cereal and Oil Food Safety Inspection and Control, Henan University of Technology, Zhengzhou 450001, China.
College of Food Science and Technology, Henan Key Laboratory of Cereal and Oil Food Safety Inspection and Control, Henan University of Technology, Zhengzhou 450001, China.
Bioelectrochemistry. 2023 Feb;149:108312. doi: 10.1016/j.bioelechem.2022.108312. Epub 2022 Oct 21.
Here, a label-free impedance-based electrochemical sensor was developed for the quantitative detection of Pb. Using conductive gold nanomaterials as electrode substrate materials can provide sensors with larger specific surface area, action sites and excellent conductivity. DNA nanostructures are used for the determination of biomolecules due to their good properties. The Y-DNA structure is formed by the annealing of three DNA sequences, which acts as a stable structure and forms a dendritic structure in combination with the hybrid chain reaction. In the presence of the target Pb, it induces the conversion of specific aptamers into G-quadruplexes, resulting in HCR and Y-DNA loading on the electrodes and a significant change in the impedance value signal. Therefore, the proposed biosensor realizes the quantitative detection of Pb. Under the optimal experimental conditions, the concentration of Pb exhibited a linear correlation range from 0.5 to1000 nmol/L with a limit of detection (LOD) of 0.38 nmol/L. The designed sensors have good recoveries in real samples (tap water and tea). This flexible experimental protocol has broad application prospects.
这里，开发了一种无标记基于阻抗的电化学传感器用于定量检测 Pb。使用导电金纳米材料作为电极基底材料可以为传感器提供更大的比表面积、作用位点和优异的导电性。由于 DNA 纳米结构具有良好的性质，因此被用于生物分子的测定。Y-DNA 结构是由三个 DNA 序列退火形成的，它作为一种稳定的结构，与杂交链式反应结合形成树突状结构。在存在目标 Pb 的情况下，它诱导特定适体转化为 G-四链体，导致 HCR 和 Y-DNA 在电极上加载，并且阻抗值信号发生显著变化。因此，所提出的生物传感器实现了对 Pb 的定量检测。在最佳实验条件下，Pb 的浓度呈现出从 0.5 到 1000 nmol/L 的线性相关范围，检测限 (LOD) 为 0.38 nmol/L。设计的传感器在实际样品（自来水和茶）中具有良好的回收率。这种灵活的实验方案具有广阔的应用前景。
