School of Biotechnology and Key Laboratory of Carbohydrate Chemistry and Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, China.
Department of Neurology, Affiliated Hospital of Jiangnan University, Wuxi 214122, China.
Anal Methods. 2024 Nov 21;16(45):7676-7682. doi: 10.1039/d4ay01608d.
DNA-templated silver nanoclusters (DNA-AgNCs) are novel nanomaterials with unique fluorescence characteristics. DNAzyme is a functional oligonucleotide that can catalyze the disruption of nucleic acid substrates. In this research, the effect of DNAzyme digestion on the fluorescence property of DNA-AgNCs was explored for the first time. A significant reduction in the fluorescence intensity of DNA-AgNCs after cleavage by DNAzyme was discovered. Further research found that the DNAzyme-catalyzed cleavage reduced the stability of DNA-AgNCs and led to their aggregation, accounting for a decline in fluorescence intensity up to 84%. Inspired by the above finding, a fluorescent aptasensor that integrates the benefits of DNA-AgNCs, exonuclease III (Exo III)-assisted signal amplification and DNAzyme was developed for sensitive detection of adenosine triphosphate (ATP). Under optimal conditions, the linear range was from 25 μM to 1000 μM and the detection limit was estimated to be 4.46 μM. Furthermore, this fluorescent aptasensor was effectively employed to quantify ATP levels in human serum samples, demonstrating its practicality in detecting ATP in biological matrices. The elucidation of DNAzyme-based fluorescence characteristic variation of DNA-AgNCs may provide insights into the interactions between DNAzyme and nanomaterials and has great prospects in the construction of fluorescent biosensors.
DNA 模板银纳米簇（DNA-AgNCs）是一种具有独特荧光特性的新型纳米材料。DNA 酶是一种具有催化功能的寡核苷酸，能够催化核酸底物的断裂。本研究首次探索了 DNA 酶对 DNA-AgNCs 荧光性质的影响。研究发现，DNA 酶切割后 DNA-AgNCs 的荧光强度显著降低。进一步的研究发现，DNA 酶催化的切割降低了 DNA-AgNCs 的稳定性，导致其聚集，荧光强度下降了 84%。受上述发现的启发，我们开发了一种将 DNA-AgNCs、核酸外切酶 III（Exo III）辅助信号放大和 DNA 酶整合在一起的荧光适体传感器，用于灵敏检测三磷酸腺苷（ATP）。在最佳条件下，线性范围为 25 μM 至 1000 μM，检测限估计为 4.46 μM。此外，该荧光适体传感器有效地用于定量人血清样品中的 ATP 水平，证明了其在生物基质中检测 ATP 的实用性。阐明 DNA 酶对 DNA-AgNCs 荧光特性变化的影响，可能有助于深入了解 DNA 酶与纳米材料之间的相互作用，并在构建荧光生物传感器方面具有广阔的前景。
