Extracellular ATP (eATP) is an important biological signal transduction molecule. Although a variety of detection methods have been extensively used in ATP sensing and analysis, accurate detection of eATP remains difficult due to its extremely low concentration and spatiotemporal distribution. Here, an eATP measurement strategy based on tetrahedral DNA (T-DNA)-modified electrode sensing platform and hybridization chain reaction (HCR) combined with G-quadruplex/Hemin (G4/Hemin) DNAzyme dual signal amplification is proposed. In this strategy, ATP aptamer and RNA-cleaving DNAzyme were combined to form a split aptazyme. In the presence of ATP, this aptazyme hydrolyzes the cleaving substrate strand with high selectivity, releasing cleaved ssDNA, which are captured by the T-DNA assembled on the electrode surface, triggering an HCR on the electrode surface to form numerous linker sequences of the HCR dsDNA product. When G-quadruplex@AuNPs (G4) spherical nucleic acid enzymes (SNAzymes) with other linkers are used as nanocatalyst tags, they are captured by HCR dsDNA through sticky linkers present on the electrode surface. An amplified electrochemical redox current signal is generated through SNAzyme-mediated catalysis of H₂O₂, enabling easy detection of picomole amounts of ATP. Using this strategy, eATP levels released by tobacco suspension cells were accurately measured and the distribution and concentration of eATP released on the surface of an Arabidopsis leaf was determined.

细胞外ATP（eATP）是重要的生物信号转导分子。尽管在ATP传感和分析中已广泛使用了多种检测方法，但是由于eATP的浓度极低且时空分布，因此准确检测eATP仍然很困难。在此，提出了一种基于四面体DNA（T-DNA）修饰的电极传感平台和杂交链反应（HCR）结合G-quadruplex / Hemin（G4 / Hemin）DNAzyme双信号扩增的eATP测量策略。在这种策略中，将ATP适体和RNA裂解DNA酶结合在一起，形成一个分裂的适体酶。在ATP存在的情况下，该适体酶以高选择性水解裂解的底物链，释放裂解的ssDNA，该ssDNA被组装在电极表面的T-DNA捕获，触发电极表面上的HCR形成HCR dsDNA产物的许多接头序列。当将带有其他接头的G-quadruplex @ AuNPs（G4）球形核酸酶（SNAzymes）用作纳米催化剂标签时，它们通过HCR dsDNA通过存在于电极表面的粘性接头捕获。通过SNAzyme介导的H催化产生放大的电化学氧化还原电流信号₂ O ₂，可轻松检测picomole量的ATP。使用这种策略，可以准确测量烟草悬浮细胞释放的eATP水平，并确定在拟南芥叶片表面释放的eATP的分布和浓度。