In this work, a novel, simple and label‐free line‐pad‐line electrode (LPLE) biosensor was developed for detection of vascular endothelial growth factor (VEGF₁₆₅). DNA aptamer was used as a recognition element for high specificity to VEGF₁₆₅, and original LPLE as the substrate electrode for high sensitivity of the biosensor. This sensor was prepared by immobilizing anti‐VEGF₁₆₅ aptamers on the LPLE surface through gold‐sulfur (Au−S) bonding. Upon the addition of VEGF₁₆₅, a large target‐induced conformational change in the surface‐immobilized aptamer was generated and caused variations in the interfacial properties,which led to a corresponding increase in the impedance magnitude of the LPLE. Finally, our results demonstrate that the calibration curve for VEGF₁₆₅determination was linear over the range of 0.026‐31.4 fM with a detection limit as low as 0.017 fM.Additionally, our sensor was fabricated on printed circuit board (PCB) with a new electrode construction, and can potentially be implemented with the advantages of simplicity, low‐cost and easy mass production. Besides, considering its desirable sensitivity and specificity, the proposed use of LPLE provided a promising strategy for a wide variety of sensing applications.

中文翻译：

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基于新型线-板-线电极的阻抗式自适应传感器测定VEGF165

在这项工作中，开发了一种新颖，简单且无标签的线垫线电极（LPLE）生物传感器，用于检测血管内皮生长因子（VEGF ₁₆₅）。DNA适体被用作对VEGF ₁₆₅高度特异性的识别元件，原始LPLE被用作生物传感器的高灵敏度底物电极。该传感器是通过金硫（Au-S）键将抗VEGF ₁₆₅适体固定在LPLE表面上制备的。加入VEGF _165后，在表面固定的适体中产生了大的目标诱导的构象变化，并引起了界面性质的变化，从而导致了LPLE的阻抗幅度相应增加。最后，我们的结果表明，VEGF ₁₆₅测定的校准曲线在0.026-31.4 fM的范围内呈线性，检出限低至0.017 fM。此外，我们的传感器在带有新电极的印刷电路板（PCB）上制造结构，并有可能以简单，低成本和易于批量生产的优势实现。此外，考虑到其理想的灵敏度和特异性，建议的LPLE使用为广泛的传感应用提供了一种有希望的策略。