基于SiO_(2)纳米颗粒的无标记化学发光氯霉素适体传感器

Label-free chemiluminescent chloramphenicol aptamer sensor based on SiO_(2) nanoparticle

经由食物链长期摄入氯霉素残留物会给人体带来各种危害和疾病。因此,建立快速、准确且高灵敏的食品中氯霉素检测方法具有重要意义。采用溶胶-凝胶法制备了表面氨基化的SiO_(2)纳米颗粒,并用X射线衍射、透射电镜和红外光谱对其进行了表征。然后,利用酰胺键和碱基互补配对作用在SiO_(2)纳米颗粒表面依次组装互补DNA链和氯霉素适配体,成功构建了无标记化学发光氯霉素适配体传感器。该传感器制备简便,其中的氯霉素适配体既可作为生物识别元件,又可与苯甲酰甲醛反应产生化学发光信号,无需标记信号分子。该传感器的氯霉素检出限为3.26×10^(-9) mol·L^(-1),且选择性较好。将该传感器应用于实际样品中进行加标,回收率在94.67%~103.00%之间,表明该适体传感器可用于食品中氯霉素的检测。

Long-term ingestion of chloramphenicol residue through the food chain is hazardous to human health and can cause diseases.Hence,it is of paramount importance to develop a rapid,precise and highly sensitive method for the detection of chloramphenicol in food.In this study,amino modified SiO_(2) nanoparticles were prepared using the sol-gel method,and analyzed through X-ray diffraction,transmission electron microscopy and infrared spectroscopy.Then,the label-free chemiluminescent chloramphenicol aptamer sensor was successfully constructed by assembling complementary DNA chains and chloramphenicol aptamers on the surface of SiO_(2) nanoparticles via amide bond and complementary base pairing,respectively.It was worth mentioning that the sensor was prepared via a facile process without labeling signal molecules,because that the chloramphenicol aptamers could react with benzoyl formaldehyde to produce chemiluminescence signal while being biorecognition elements.The as-prepared sensor showed a low detection limit of chloramphenicol(3.26×10^(-9) mol·L^(-1))and good specificity.Further,the proposed sensor was applied to realize samples with recoveries ranging from 94.67%to 103.00%,demonstrating its feasibility of detecting chloramphenicol in food.