基于DNA核酸适配体序列的超灵敏比色法检测牛乳中的雌二醇

发布时间：2018-10-29 15:19

【摘要】：分别利用最适长度的雌二醇DNA核酸适配体的特异性识别和胶体金聚集前后颜色及吸光度的变化实现雌二醇的定性和定量检测。本研究制备了胶体金,并设计了75-mer、35-mer和22-mer的雌二醇核酸适配体,依据没有核酸适配体保护的胶体金在最适氯化钠浓度条件下聚集,而有核酸适配体保护的胶体金在此浓度条件下不聚集以及雌二醇的核酸适配体与雌二醇特异性结合的特性,实现对雌二醇的超灵敏检测。结果表明,在Na Cl浓度30 mmol/L、35-mer核酸适配体质量浓度30 nmol/L条件下,雌二醇质量浓度与胶体金在625 nm和523 nm波长条件下,吸光度的比值(A_(625) nm/A_(523) nm)在13.6~54.4 pg/m L的范围内呈良好的线性关系,检测限为2.7 pg/m L。所构建的比色法的特异性、稳定性和重复性均良好。应用该方法对牛乳样品进行检测,雌二醇的最低检测限为13.6 pg/m L,因此可用于奶制品中雌二醇的快速检测。
[Abstract]:The qualitative and quantitative detection of estradiol was carried out by using the specific recognition of the aptamer of estradiol DNA nucleic acid and the changes of color and absorbance before and after colloidal gold aggregation. In this study, colloidal gold was prepared, and the estradiol aptamers of 75-mercan35-mer and 22-mer were designed. The colloidal gold without aptamer of nucleic acid was aggregated at the optimum concentration of sodium chloride. However, the colloidal gold protected by aptamer of nucleic acid does not gather at this concentration and the specific binding property of the aptamer of estradiol to estradiol, so that the hypersensitive detection of estradiol can be achieved. The results showed that the mass concentration of estradiol and colloidal gold were at 625 nm and 523 nm wavelength under the condition of Na Cl concentration 30 mmol/L,35-mer nucleic acid body weight concentration 30 nmol/L, and the mass concentration of estradiol and colloidal gold at 625 nm and 523 nm wavelength, respectively. The ratio of absorbance (A _ (625) nm/A_) (523) nm) was linear in the range of 13.6n 54.4 pg/m / L, and the detection limit was 2.7 pg/m / L. The constructed colorimetric method has good specificity, stability and reproducibility. The minimum detection limit of estradiol is 13.6 pg/m / L, so it can be used for rapid detection of estradiol in dairy products.
【作者单位】：浙江省动物蛋白精深加工技术重点实验室;南京师范大学国家乳品加工技术研发分中心;
【基金】：“十二五”国家科技支撑计划项目(2015BAD17B02-3) 浙江省攻关项目(2014C02020)
【分类号】：TS252.7;O657.3

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