This communication describes a simple sensitive one-step potentiometric aptasensing method for quantitative detection of a referenced therapeutic biomarker (programmed death-ligand 1, PD−L1). The aptasensor is constructed by modifying PD−L1-specific aptamer on Ti₃C₂-MXene nanosheets-functionalized electrode. Introduction of PD−L1 induces the specific reaction between PD−L1 and aptamer, thereby resulting in the change of spatial structures. The surface electric potential of modified electrode is shifted upon addition of PD−L1 proteins before and after the reaction of aptamer with the analyte. Interestingly, potentiometric aptamer with Ti₃C₂-MXene nanosheets can achieve a higher sensitivity and a lower detection limit toward target PD−L1 relative to aptamer-modified electrode. Experimental results indicated that the linear range and detection limit of using Ti₃C₂-MXene nanosheets were 0.01–100 ng mL⁻¹ and 7.8 pg mL⁻¹ PD−L1, respectively. Meanwhile, the specificity, reproducibility, storing stability and accuracy of potentiometric aptasensor are acceptable for the screening of PD−L1 in human serum samples.

中文翻译：

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适配体功能化 Ti3C2-MXene 纳米片与程序性死亡配体 1 的一步电位检测

该通讯描述了一种简单灵敏的一步电位适体传感方法，用于定量检测参考治疗性生物标志物（程序化死亡配体 1，PD-L1）。_{适配体传感器是通过在 Ti 3} C ₂ -MXene 纳米片功能化电极上修饰 PD-L1 特异性适配体而构建的。PD-L1的引入诱导PD-L1与适体发生特异性反应，从而导致空间结构的变化。在适配体与分析物反应之前和之后添加 PD-L1 蛋白，修饰电极的表面电位发生变化。_{有趣的是，具有 Ti 3} C ₂的电位适体-MXene 纳米片相对于适配体修饰电极可以实现更高的灵敏度和对目标 PD-L1 的更低检测限。实验结果表明，使用 Ti ₃ C ₂ -MXene 纳米片的线性范围和检测限分别为 0.01-100 ng mL ^-1和 7.8 pg mL ^-1 PD-L1。同时，电位适体传感器的特异性、重现性、储存稳定性和准确性对于人血清样本中PD-L1的筛选是可以接受的。