核酸适体-捕获探针预杂交修饰制备免标记腺苷电化学传感器

Aptamer-capture-prehybridization-modification for label-free adenosine electrochemical sensor

核酸适体(Aptamer)是单链寡核苷酸片段,对靶分子具有高亲和力和高特异性,具有常规识别分子(如抗体和酶)所不具备的一些优点,该文基于核酸适体制备了一种用于检测腺苷的免标记电化学传感器。将腺苷的核酸适体与带巯基的捕获探针通过硫-巯键组装到金电极表面,用6-巯基己醇(MCH)作为缺陷探针封闭电极表面,得到的MCH/Aptamer-Capture/Au界面,构筑的电化学传感器对腺苷具有特异性识别功能,检测腺苷的线性范围为1×10-6mol/L^2.5×10-4mol/L,检测限为0.1μmol/L,相对标准偏差(R.S.D)为2.0%。该传感器对腺苷的检测具有灵敏度高、检测范围宽、制作简便、成本低,并且具有良好的选择性和重现性。

Compared with conventional recognition molecules （such as antibodies and enzyme）, aptamer as an oligonucleotide clip has hiwgh affinity and high specificity of target molecules.. Herein, we prepared a label-free ap- tamer electrochemical biosensor for the detection of adenosine. Firstly, the cleaned gold electrode covalently bonded the aptamer-capture system and then the Aptamer-Capture/Au electrode was immersed into 2-Mercaptoethanol （MCH） solution to prepare the MCH/Aptamer-Capture/Au-based electrochemical sensor. It can specifically identi- fy the adenosine for the detection linear range from 1×10-6 to 2.5×10-4 mol/L with the detection limit of 0.1 μmol/L. On the same condition, the detection of the same concentration of adenosine, the relative standard deviation （R.S.D） was about 2.0%. The resultant adenosine sensor has high sensitivity, wide detection range, easy-made process, low cost as well as good selectivity and reproducibility.