FAD核酸适配体生物传感器的制备及其葡萄糖检测的应用

以纳米金（gold nanoparticles，AuNPs）为主体，甲烷氧化菌素（methanobactin，Mb）和黄素腺嘌呤二核苷酸（flavin adenine dinucleotide，FAD）为配体构建FAD核酸适配体传感器。利用AuNPs颗粒较强的吸附能力，将Mb包裹于纳米颗粒上，形成稳定的Mb-AuNPs结构体。采用滴涂法将Mb-AuNPs结构体修饰于裸金电极表面，借助Mb结构中的—COOH与FAD牢固结合，将FAD引入Mb-AuNPs结构体上，提高对葡萄糖的识别能力，从而构建具备葡萄糖氧化酶活性的新型核酸适配体生物传感器。通过循环伏安法及时间-电流曲线法探讨其应用于葡萄糖检测的可行性。在温度25 ℃、pH 7.2时，葡萄糖浓度为10～200 μmol/L，与该生物传感器的响应电流存在良好的线性关系，R2为0.997 91，检出限为4.22×10－8 mol/L（RSN=3）。该核酸适配体传感器具有制备简单、价格低廉、易于操作、可快速检测等优点。

Preparation of Flavin Adenine Dinucleotide Aptamer-Based Sensor and Its Application for Glucose Detection

An flavin adenine dinucleotide (FAD) aptamer-based sensor was constructed with gold nanoparticles (AuNPs) as the main body, and methanobactin (Mb) and FAD as the ligands. Mb was used to wrap AuNPs, which has a strong adsorption capacity for Mb, to form a stable Mb-AuNPs structure. The Mb-AuNPs structure was used to modify the surface of the bare gold electrode by the drip-coating method, and FAD was introduced into the Mb-AuNPs structure, in which the –COOH groups could firmly bind to FAD, to improve the ability to recognize glucose. As a result, a novel aptamer biosensor with glucose oxidase-like activity could be constructed. Cyclic voltammetry and the time-current curve method were used to explore the feasibility of its application in glucose detection. At 25 ℃ and pH 7.2, there was a good linear relationship between glucose concentration in the range of 10–200 mmol/L and the response current of the biosensor, with a correlation coefficient (R2) of 0.997 91, and the detection limit was 4.22 × 10-8 mol/L (RSN = 3). The aptamer-based sensor has several advantages such as simple preparation, low price, easy operation and rapid detection.