As various aptasensors are adopted in clinical diagnosis, the development of convenient multiple-target determination is a field of ever-increasing interests. Herein, a label-free and amplified electrochemiluminescence (ECL) sensing platform was constructed to detect multiple targets of hemin, glucose and thrombin (TB) using peroxydisulfate (S₂O₈²⁻) solution, which was one of the most convenient and economical ECL systems. It was worth mentioning that the target-induced bi-enzyme cascade catalysis reaction was developed to increase the ECL response strongly of S₂O₈²⁻ solution due to the production of (¹O₂)₂* from the inter-reaction between reactive oxygen species (ROS) and sulfate radical (SO₄•−). Specifically, with the layer-by-layer assembly of multi-walled carbon nanotubes (MWCNTs), glucose oxidase (GOx) and gold nanoparticles (AuNPs) as the interface, the guanine-rich (G-rich) thrombin aptamer (TBA) was anchored for hemin (target 1) detection, due to the electrocatalysis of hemin/G-quadruplex as a horseradish peroxidase mimicking DNAzyme (HRP-DNAzyme) towards dissolved oxygen for ROS generation. Second, in the presence of glucose (target 2), the ECL intensity was improved because glucose was the substrate of the bi-enzyme cascade catalysis reaction. Third, when TB (target 3) was sequentially incubated based on the above-mentioned aptasensor, the bi-enzyme catalysis was inhibited to decrease the ECL signal, due to the steric hindrance effect of the TB protein. As a result, the aptasensor achieved the nanomolar detection for hemin (3.33 nM), the micromolar detection for glucose (0.33 μM) and the femtomolar detection for TB (3.33 fM), respectively.

随着各种适体传感器在临床诊断中的应用，方便的多靶点测定的发展是一个越来越受关注的领域。本文构建了一种无标记的放大电化学发光（ECL）传感平台，使用过硫酸盐（S ₂ O ₈ ^2-）溶液检测血红素、葡萄糖和凝血酶（TB）的多个靶标，这是最方便、最经济的方法之一。 ECL 系统。值得一提的是，由于生成 ( ¹ O ₂ ) _{2 ，开发了靶标诱导的双酶级联催化反应，以强烈增加 S 2} O ₈ ^{2-溶液的 ECL 响应。}* 来自活性氧 (ROS) 和硫酸根 (SO ₄•−)。具体而言，以多壁碳纳米管（MWCNTs）、葡萄糖氧化酶（GOx）和金纳米颗粒（AuNPs）为界面，逐层组装形成富含鸟嘌呤（G-rich）的凝血酶适体（TBA）。由于血红素/G-四链体作为辣根过氧化物酶模拟脱氧核糖核酸酶（HRP-脱氧核糖核酸酶）对溶解氧产生 ROS 的电催化作用，锚定用于血红素（目标 1）检测。其次，在存在葡萄糖（目标 2）的情况下，由于葡萄糖是双酶级联催化反应的底物，因此 ECL 强度得到了提高。第三，当基于上述适体传感器连续孵育TB（靶标3）时，由于TB蛋白的空间位阻效应，双酶催化被抑制，ECL信号降低。结果，适体传感器实现了对血红素的纳摩尔检测（3.