Challenged by the detection of trace amounts of mutants and disturbance from endogenous substances in clinical samples, herein, we present a novel electrochemical biosensor based on ligase chain reaction (eLCR) via the thermostable ligase with high mutation recognizing ability. The lengthened double-stranded DNAs exponentially generated via LCR were uniformly distributed on a bovine serum albumin-modified gold electrode, in which the phosphate buffer was tactfully added to remove adsorbed uninterested-probes, and thereafter the amperometry current was collected for the specific binding of streptavidin-poly-HRP and subsequent catalysis in the 3, 3′, 5, 5′-tetramethylbenzidine substrate that contained hydrogen peroxide. It found that, under optimized conditions, the proposed biosensor exhibited a high selectivity of mutant targets from the 10⁴-fold excess of co-existent wild targets within a detection limit of 0.5 fM. Impressively, without the involvement of pre-PCR, the homozygous mutants were specifically distinguished from the wild genotype of CYP2C19*2 allele in human whole blood samples. Therefore, the proposed eLCR, due to its advantages in simple primer design, operational ease and ease of miniaturization, has demonstrated its considerable potential for point-of-care testing in the diagnosis of point mutation-related diseases and personalized medicine.

面临的挑战是从临床样品中检测到痕量的突变体和来自内源性物质的干扰，在此，我们提出了一种基于连接酶链反应（eLCR）的新型电化学生物传感器，该传感器通过具有高突变识别能力的热稳定连接酶来实现。将通过LCR指数生成的加长双链DNA均匀地分布在牛血清白蛋白修饰的金电极上，在其中巧妙地添加磷酸盐缓冲液以去除吸附的无关探针，然后收集电流分析电流以特异性结合链霉亲和素-poly-HRP，随后在含有过氧化氢的3，3'，5，5'-四甲基联苯胺底物中催化。结果发现，在最佳条件下，拟议的生物传感器对10个突变体靶标具有很高的选择性。在0.5 fM的检出限内，共存野生靶标过量⁴倍。令人印象深刻的是，在不进行前PCR的情况下，纯合突变体与人全血样品中CYP2C19 * 2等位基因的野生基因型有明显区别。因此，由于所提出的eLCR在引物设计简单，操作简便和小型化方面的优势，已证明其在诊断与点突变相关的疾病和个性化药物方面的即时检测具有巨大潜力。