Sensitive detection and quantification of cytokines can play important roles in immunology research and diseases diagnosis. In this regard, by using a new target-triggered programming of cascaded catalytic hairpin assembly (CHA) signal enhancement strategy, we have developed an enzyme-free approach for the highly sensitive detection of cytokines, where interferon-γ (IFN-γ) is selected as the target model molecule. IFN-γ associates with a hairpin aptamer probe and triggers a conformation change of the aptamer to expose an initiation sequence for the formation of three independent and cascaded CHA of four hairpins into dsDNAs, which results in drastically enhanced fluorescence recovery from the fluorescently quenched hairpin signal probes for detecting IFN-γ in a dynamic range between 0.001 and 50 nM with detection limit down to 0.6 pM. Furthermore, this elaborately designed signal amplified approach displays efficient selectivity for the target molecules and can realize the detection of IFN-γ in diluted human serums, demonstrating its potential for monitoring a variety of biomarkers with high sensitivity by using appropriate hairpin aptamer/target molecule pairs.

细胞因子的敏感检测和定量在免疫学研究和疾病诊断中可以发挥重要作用。在这方面，通过使用级联催化发夹组件（CHA）的信号增强策略的一个新的目标触发编程，我们已经开发了用于高度灵敏地检测细胞因子，其中干扰素γ不含酶的方法（IF N- γ）选择作为靶模型分子。如果N- γ与发夹适体探针结合并触发适体构象变化，以暴露起始序列，从而将四个发夹的三个独立且级联的CHA形成为dsDNA，从而导致荧光淬灭的发夹的荧光回收率大大提高。用于检测IF N-的信号探头γ在0.001至50 nM的动态范围内，检出限低至0.6 pM。此外，这种精心设计的信号放大方法对目标分子显示出有效的选择性，并且可以实现对稀释的人血清中IF N- γ的检测，从而证明了其通过使用适当的发夹适体/目标分子以高灵敏度监测多种生物标志物的潜力。对。