Nucleic acid-based probes have been widely exploited for biosensing by virtue of their excellent physicochemical and ease synthesis properties. Given that the aggregation-induced emission, and hydrogen peroxide (H₂O₂) can be converted hydroxyl radical (·OH) to cleave nucleic acids, a new nucleic acid-based probe has been developed for H₂O₂ assay. Herein, a novel carbazole derivative of 3-(3-(2-(1-ethylquinolin-1-ium-4-yl)vinyl)-9H-carbazol-9-yl)propanoate (EVCP) was designed with enhanced fluorescence signal by G-quadruplex labeled with FAM (G-FAM/EVCP), in which there was a fluorescence resonance energy transfer (FRET) effect between EVCP and the labeled FAM. In this assay, the probe of G-FAM/EVCP exhibited high fluorescent signal of EVCP in the absence of H₂O₂, yet a decrease of EVCP emission intensity but an increase in that of FAM in the presence of H₂O₂, due to the cleavage of G-FAM/EVCP to short-oligonucleotide fragments by ·OH generated from Fenton reaction, eliminating the FRET effect and achieving H₂O₂ assay. The nucleic acid-based ratiometric probe was further applied for oxidase-based biosensing using H₂O₂ as a mediator. Results demonstrated that our proposed strategy had great potential for biochemical and clinical applications.

基于核酸的探针因其出色的物理化学和易于合成的特性而被广泛用于生物传感。鉴于聚集诱导的发射和过氧化氢（H ₂ O ₂）可以被转换成羟基（·OH）以切割核酸，因此针对H ₂ O ₂开发了一种新的基于核酸的探针分析。本文设计了一种新型的3-（3-（2-（1-乙基喹啉-1-基-4-基）乙烯基）-9H-咔唑-9-基）丙酸酯（EVCP）咔唑衍生物，其荧光信号通过用FAM标记的G四联体（G-FAM / EVCP），其中EVCP和标记的FAM之间存在荧光共振能量转移（FRET）效应。在该测定中，G-FAM的探针/ EVCP在没有h的显示EVCP的高荧光信号₂ ö ₂，但EVCP发射强度的降低，但在H存在的增加在FAM的₂ Ò ₂，由于Fenton反应产生的·OH将G-FAM / EVCP裂解为短寡核苷酸片段，从而消除了FRET效应并实现了H ₂ O ₂分析。使用H ₂ O ₂作为介体，将基于核酸的比例探针进一步应用于基于氧化酶的生物传感。结果表明，我们提出的策略在生化和临床应用中具有巨大的潜力。