Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, Jinhua, 321004, Zhejiang, PR China.
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, Jinhua, 321004, Zhejiang, PR China.
Anal Chim Acta. 2024 Mar 22;1295:342320. doi: 10.1016/j.aca.2024.342320. Epub 2024 Feb 1.
G-quadruplex (G4)/hemin DNAzymes with conversion of substrates into colorimetric readouts are well recognized as convenient biocatalysis tools in sensor development. However, the previously developed colorimetric G4/hemin DNAzymes are diffusive substrate-based DNAzymes (DSBDs). The current colorimetric DSBDs have several drawbacks including high dosage (∼mM) of diffusive substrates (DSs), colorimetric product toxicity, and single colorimetric readout without tolerance to fluctuation of experimental factors and background. In addition, the usage of high-dosage DSs can smear the G4 foldings and their discard is more harmful to environment. Therefore, exploring alternative DNAzymes with potential to overcome these drawbacks of DSBDs is urgently needed.
We herein developed associative substrate-based DNAzymes (ASBDs). Cyanine dyes were selected as associative substrates (ASs) due to their binding competency with G4/hemin DNAzymes. With respect to DSBDs, ASBDs needed only low dosage (∼10 μM) of ASs to be able to cause a rapid and visible substrate conversion. In addition, since cyanine dyes are NIR dyes with high extinction coefficients and their conversion products have absorption bands at shorter wavelength. Therefore, a colorimetric ratio response can be developed to follow activities of G4/hemin DNAzymes with competency to tolerate fluctuation of experimental factors and background. In particular, herein developed ASBDs can endure somewhat concentration fluctuation of HO. ASBDs are able to cowork with other enzymes (for example, glucose oxidase) to realize cascade sensing.
The developed ASBDs can operate at low dosage of substrates with a colorimetric ratio response and can overcome the drawbacks met in DSBDs. We expect that, by designing ASs with fruitful color panel in the future, our work will inspire more interesting in developing environment-benign and low-carbon G4/hemin DNAzymes and desired colorful high-performance sensors.
将底物转化为比色读出信号的 G-四链体（G4）/血红素 DNA 酶已被广泛认可为传感器开发中方便的生物催化工具。然而，以前开发的比色 G4/血红素 DNA 酶是扩散底物（DS）基 DNA 酶（DSBD）。目前的比色 DSBD 存在几个缺点，包括扩散底物（DS）用量高（约 mM）、比色产物毒性以及单一比色读数，不具有对实验因素和背景波动的容忍度。此外，高剂量 DS 的使用会掩盖 G4 折叠，而且它们的丢弃对环境的危害更大。因此，迫切需要探索具有克服 DSBD 这些缺点潜力的替代 DNA 酶。
我们在此开发了缔合底物基 DNA 酶（ASBD）。由于与 G4/血红素 DNA 酶具有结合能力，我们选择菁染料作为缔合底物（AS）。与 DSBD 相比，ASBD 只需要低剂量（约 10 μM）的 AS 即可快速、明显地进行底物转化。此外，由于菁染料是具有高消光系数的近红外染料，并且它们的转化产物在较短波长处具有吸收带。因此，可以开发比色比率响应来跟踪 G4/血红素 DNA 酶的活性，具有对实验因素和背景波动的容忍度。特别地，在此开发的 ASBD 可以承受 HO 浓度的波动。ASBD 能够与其他酶（例如葡萄糖氧化酶）一起工作以实现级联传感。
开发的 ASBD 可以在低剂量底物下以比色比率响应运行，并克服 DSBD 中遇到的缺点。我们期望，通过设计未来具有丰富色彩面板的 AS，我们的工作将激发更多人开发环境友好和低碳的 G4/血红素 DNA 酶以及所需的高性能彩色传感器的兴趣。
