The detection of single-nucleotide variants (SNVs) in circulating tumor DNA (ctDNA) in liquid biopsies has increasingly been shown to exhibit unique benefits for early detection or minimal residual disease monitoring in cancer. Yet, current clinically validated assays for ctDNA SNV detection are challenged by (i) time-consuming and laborious spin column-based ctDNA purification protocols, (ii) limited detection specificity to discriminate between mutated SNVs from large excess of closely similar wild-type sequences, and (iii) insufficient detection sensitivity required for trace ctDNA target analysis in blood. Herein, a ctDNA assay is demonstrated to tackle these triple key issues by fusing magnetics for quick ctDNA enrichment directly from unprocessed blood, selected bioenzyme activities for rapid discrimination, and molecular amplification of target SNVs, and designed magnetic-assisted bioelectrocatalytic cycling of DNA-intercalating and freely diffusing redox probes for electrochemical signal intensification. The described ctDNA SNV assay enables the detection of clinically relevant ctDNA SNVs in melanoma (BRAF^V600E, KIT^L576P, and NRAS^Q61K) from unprocessed plasma samples with unprecedented 0.005% detection sensitivity, ultrabroad dynamic range over four orders of magnitude, and excellent single-base specificity.

中文翻译：

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通过电磁辅助生物电催化循环直接增强未处理血浆中多种循环肿瘤DNA变体的检测。

液体活检中循环肿瘤DNA（ctDNA）中单核苷酸变体（SNV）的检测越来越多地显示出对癌症的早期检测或最小残留疾病监测的独特优势。然而，当前针对ctDNA SNV检测的临床验证试验受到以下挑战：（i）耗时且费力的基于旋转柱的ctDNA纯化方案，（ii）有限的检测特异性，无法从大量过量的紧密相似的野生型序列中区分突变的SNV （iii）血液中痕量ctDNA靶标分析所需的检测灵敏度不足。本文证明了ctDNA检测方法可解决这些三重问题，方法是将磁性材料直接从未加工的血液中快速融合富集的ctDNA，并通过选择的生物酶活性进行快速鉴别，分子和目标SNV的分子扩增，并设计了DNA插入和自由扩散氧化还原探针的磁辅助生物电催化循环，用于电化学信号增强。所描述的ctDNA SNV分析能够检测黑素瘤中临床相关的ctDNA SNV（来自未处理血浆样品的BRAF ^V600E，KIT ^L576P和NRAS ^Q61K）具有前所未有的0.005％的检测灵敏度，超过四个数量级的超宽动态范围以及出色的单碱基特异性。