比色法检测Hg2+的DNAzyme生物传感器的构建

Construction of DNAzyme biosensor for the detection of Hg2+ by colorimetry

中文关键词:  比色法  二价汞离子  脱氧核酶  生物传感器

英文关键词:colorimetry  divalent mercury ion  deoxyribozyme  biosensor

中文摘要:

      目的 构建一种脱氧核酶(deoxyribozyme, DNAzyme)生物传感器用于比色法定量检测水源中的Hg2+污染物。方法 借助核酸外切酶Ⅰ设计富含鸟嘌呤的功能核酸序列(HA-PS2.M), 并对影响DNAzyme生物传感器响应效果的氯化血红素(hemin)浓度、K+浓度和2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸[2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic, ABTS]体积进行响应面优化。结果 成功构建了可用于比色法定性定量检测水源中的Hg2+污染物的DNAzyme生物传感器, Hg2+在25~500 nmol/L浓度范围内线性关系良好, 相关系数r2为0.9868, 方法的回收率为98.96%~102.23%, 相对标准偏差≤4.86%, 检出限为3.5 nmol/L。结论 该DNAzyme生物传感器无需修饰、合成简单, 具有较高的准确度、灵敏度和稳定性, 适用于水源中Hg2+污染的检测。

英文摘要:

      Objective To construct a DNAzyme biosensor for the colorimetric detection of Hg2+ pollutants in water sources. Methods A guanine-rich functional nucleic acid sequence (HA-PS2.M) was designed with the help of exonuclease I and the factors of hemin concentration, K+ concentration and ABTS volume that affect the response of the DNAzyme biosensor were optimized by response surface methodology. Results A DNAzyme biosensor was successfully constructed, which could be used for qualitative and quantitative detection of Hg2+ pollutants in water by colorimetric method, the linear relationship of Hg2+ was good in the concentration range of 25-500 nmol/L with the correlation coefficient r2=0.9868, the recoveries of Hg2+ ranged from 98.96% to 102.23% with the relative standard deviation of less than 4.86%, and the detection limit was 3.5 nmol/L. Conclusion The DNAzyme biosensor is simple to synthesize without modification and has high accuracy, sensitivity and stability. It is suitable for the detection of Hg2+ pollution in water sources.