AbstractA colorimetric detection scheme is introduced for the determination of alkaline phosphatase (ALP) activity based on Cu(II)-modulated G-quadruplex-based DNAzymes. It is exploiting the strong affinity of Cu(II) for pyrophosphate (PPi) upon which the cofactor PPi is trapped by Cu(II). Hence, the activity of the DNAzyme is inhibited. ALP catalyzes the hydrolysis of PPi, causing the release of Cu(II). DNAzyme, in turn, is activated and catalyzes the cleavage of the DNA probe substrate. The released G-rich sequence folds into the G-quadruplex, which can bind hemin and catalyze the oxidation of 2,2′-azinobis (3-ethylbenzothiozoline)-6-sulfonate (ABTS), and this leads to an increase in absorbance at 420 nm. Absorbance increases linearly with increasing ALP activity in 0.07 to 300 U.L−1 range, with a 70 mU.L−1 detection limit. The method was applied in ALP inhibition tests and to the determination of ALP activity in spiked serum samples where it gave satisfactory results. Graphical abstractA colorimetric method has been developed for the detection of alkaline phosphatase based on the use of Cu(II)-modulated G-quadruplex-based DNAzymes.

中文翻译：

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基于使用 Cu(II) 调节的 G-四链体 DNAzymes 的碱性磷酸酶活性的比色测定

摘要 介绍了基于 Cu(II) 调节的 G-四链体 DNAzymes 测定碱性磷酸酶 (ALP) 活性的比色检测方案。它利用 Cu(II) 对焦磷酸盐 (PPi) 的强亲和力，辅因子 PPi 被 Cu(II) 捕获。因此，DNAzyme 的活性受到抑制。ALP 催化 PPi 的水解，导致 Cu(II) 的释放。反过来，DNAzyme 被激活并催化 DNA 探针底物的裂解。释放的富含 G 的序列折叠成 G-四链体，它可以结合血红素并催化 2,2'- azinobis (3-ethylbenzothiozoline)-6-sulfonate (ABTS) 的氧化，这导致吸光度增加420 纳米。在 0.07 到 300 UL-1 范围内，吸光度随着 ALP 活性的增加而线性增加，检测限为 70 mU.L-1。该方法应用于 ALP 抑制试验和测定加标血清样品中的 ALP 活性，结果令人满意。图形摘要基于使用 Cu(II) 调制的基于 G-四链体的 DNA 酶，开发了一种用于检测碱性磷酸酶的比色方法。