In this work, a novel electrochemiluminescence (ECL) biosensor was fabricated to detect the mutant KRAS gene in the tumor tissues. Firstly, a new kind of chitosan-based dots was prepared and regulated by phenylboronic acid (PBA) as ECL nanoprobe. Furthermore, the electrochemically deposited Ag structures with controllable morphology have been developed on the electrode. The detailed electrochemical deposition condition of Ag structure has been investigated deeply. Due to the synergistic effect of the large active surface area and the high conductivity, the layered Ag flower-like structure with branches can significantly enhance the ECL intensity of CS-PBA dots by 12.1 times. Finally, the toehold mediated strand displacement strategy was employed in the ECL biosensor to quantitatively detect mutant KRAS gene with the range of 0.01 pM to 10 nM. The limit of detection was 3.3 fM. This biosensor has been used successfully to analyze the target DNA in the tumor tissues of actual cancer patients. The results showed the novel sensing platform possessed great potential for clinical analysis.

在这项工作中，制造了一种新型电化学发光（ECL）生物传感器来检测肿瘤组织中的突变 KRAS 基因。首先，制备了一种新型壳聚糖基点，并以苯硼酸（PBA）作为ECL纳米探针进行调控。此外，已经在电极上开发了具有可控形态的电化学沉积Ag结构。对Ag结构的详细电化学沉积条件进行了深入研究。由于大活性表面积和高电导率的协同作用，带分支的层状Ag花状结构可以显着提高CS-PBA点的ECL强度12.1倍。最后，在 ECL 生物传感器中采用 toehold 介导的链置换策略定量检测突变 KRAS 基因，范围为 0.01 pM 至 10 nM。检测限为 3.3 fM。该生物传感器已成功用于分析实际癌症患者肿瘤组织中的目标 DNA。结果表明，新型传感平台具有巨大的临床分析潜力。