功能性核酸增强Hemin催化活性用于乳制品中四环素检测研究

Tetracycline Detection in Dairy Products by Using Hemin with Functional Nucleic Acid-enhanced Catalytic Activity

摘要:

为了建立一种便捷有效的四环素残留比色检测方法，本研究先用富含鸟嘌呤的单链脱氧核糖核酸(G-ssDNA)序列，增强氯化血红素（Hemin）辣根过氧化物酶活性，使其氧化底物3,3',5,5'-四甲基联苯胺（TMB）形成黄色产物。当体系中加入四环素后，则Hemin的催化活性被抑制，从而氧化底物形成蓝色产物。通过测定产物吸收光谱的变化，可以测定四环素的含量。在最优检测条件下，该方法测定四环素浓度在10 nM~100 nM范围内呈现良好的线性关系，线性相关系数为0.994，最低检测限为5.69 nM。特异性实验证实其它抗生素类似物对四环素检测无明显交叉反应。将该方法用于实际牛奶样品检测，对四环素的检测回收率为92%~99%。本研究所建立的方法具有特异性好、操作方便等优点，不需要依赖大型仪器就可以对四环素进行快速检测，因而可广泛应用于乳制品中四环素残留检测。

Abstract:

In order to establish a convenient and effective method for the colorimetric detection of tetracycline (TET) residues, guanine-rich single stranded deoxyribonucleic acid (G-ssDNA) was first used to enhance the horseradish peroxidase activity of hemin, which oxidized 3,3?,5,5?-tetramethylbenzidine (TMB) to form a yellow product. With the addition of TET in the system, the catalytic activity of hemin was suppressed, and the substrate was oxidized to form a blue product. The TET content could be determined by measuring the change in the absorption spectra of the reaction products. Under optimal measurement conditions, the proposed method has a detection limit of 5.69 nM, and a linear range from 10 nM to 100 nM, with a correlation coefficient of 0.994. The specificity test confirmed that other related antibiotics did not show significant cross-reactivity with the TET measurement. This method was used to detect TET in milk samples, and the spiked recoveries for TET detection were in the range of 92% to 99%. The advantages of the method established in this work include high specificity and convenient operation. In addition, the method allows for rapid TET detection without relying on large instruments, and thus can be widely used for the detection of TET residues in dairy products.