在本研究中，金纳米颗粒@Ti3C2 MXenes纳米复合材料与趾状介导的DNA链置换反应相结合，构建了一种电化学循环肿瘤DNA生物传感器，具有优异的性能。金纳米颗粒是在Ti3C2 MXenes表面原位合成的还原和稳定剂。金纳米颗粒@Ti3C2 MXenes复合材料的良好电导性和无酶趾状介导的DNA链置换反应的核酸扩增策略，可用于高效、特异性地检测非小细胞癌生物标志物循环肿瘤DNA KRAS基因。该生物传感器具有10 fM -10 nM的线性检测范围和0.38 fM的检测限，并能有效区分单碱基错配的DNA序列。该生物传感器已成功用于敏感检测KRAS基因G12D，具有优秀的临床分析潜力，并为制备新型MXenes基二维复合材料及其在电化学DNA生物传感器中的应用提供了新思路。版权所有 © 2023 Yu、Bai和Wang。

In this work, gold nanoparticles@Ti3C2 MXenes nanocomposites with excellent properties were combined with toehold-mediated DNA strand displacement reaction to construct an electrochemical circulating tumor DNA biosensor. The gold nanoparticles were synthesized in situ on the surface of Ti3C2 MXenes as a reducing and stabilizing agent. The good electrical conductivity of the gold nanoparticles@Ti3C2 MXenes composite and the nucleic acid amplification strategy of enzyme-free toehold-mediated DNA strand displacement reaction can be used to efficiently and specifically detect the non-small cell cancer biomarker circulating tumor DNA KRAS gene. The biosensor has a linear detection range of 10 fM -10 nM and a detection limit of 0.38 fM, and also efficiently distinguishes single base mismatched DNA sequences. The biosensor has been successfully used for the sensitive detection of KRAS gene G12D, which has excellent potential for clinical analysis and provides a new idea for the preparation of novel MXenes-based two-dimensional composites and their application in electrochemical DNA biosensors.Copyright © 2023 Yu, Bai and Wang.