中文摘要：

本文报道了一种基于DNAzyme的可视检测单链核酸酶活性的新方法。DNAzyme是一种具有类过氧化物酶活性的单链DNA分子,在H2O2存在下能够催化无色底物2,2′-连氮基-双-（3-乙基并二氢噻唑啉-6-磺酸）二价阴离子（ABTS^2-）氧化成蓝绿色物质ABTS^-.自由基。催化体系中单链核酸酶的加入能水解DNAzyme,导致被DNAzyme催化的ABTS^-.减少,从而可以通过颜色变化和紫外-可见吸收光谱检测相应的单链核酸酶活性。以DNase I和S1核酸酶作为单链核酸酶代表进行实验,实验结果表明对DNase I检测的线性范围为0.5-5 U/mL,检出限为0.15 U/mL;对S1核酸酶检测的线性范围为1-10 U/mL,检出限为0.11 U/mL。该方法还能用于单链核酸酶抑制剂的检测,结果表明：Zn2＋对DNase I的半数抑制浓度（Ic50）为56.4 mol/L,焦磷酸盐对S1核酸酶的Ic50为1.17 mmol/L。

英文摘要：

A new method for visual detection of the activity of single-strand specific（SSS） nuclease based on DNAzyme was developed.Due to its peroxidase-like activitiy,DNAzyme can catalyze oxidation of the colorless 2,2′-azino-bis（3-etylbenzthiazoline-6-sulphonate） dianion（ABTS^2-） mediated by H2O2 to the green radical anion（ABTS^-·）.SSS nuclease can hydrolyze DNAzyme which is single-strand nucleotide,resulting in the reducing of ABTS^-·.Therefore,the activity of SSS nuclease can be detected through the changes of color and UV-Vis absorption spectra. Choosing DNase I and S1 as model nucleases, the linear response range was 0.5-5 U/mL for DNase I with a detection limit of 0.15 U/mL, and the linear response range was 1-10 U/mL for S1 with a detection limit of 0. 11 U/mL. This method was also successfully used for the detection of the SSS nuclease inhibitors. The Ic50 （the inhibitor concentration required to reduce enzyme activity by 50%） of Zn^2＋ is 56. 4 μmol/L for DNase I and Ic50 of pyrophosphate is 1.17 mmol/L for S1.