Ma Xiaoyuan, Jiang Yihui, Jia Fei, Yu Ye, Chen Jie, Wang Zhouping
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, 214122, China.
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.
J Microbiol Methods. 2014 Mar;98:94-8. doi: 10.1016/j.mimet.2014.01.003. Epub 2014 Jan 17.
Salmonella is one of the most common causes of food-associated disease. An electrochemical biosensor was developed for Salmonella detection using a Salmonella-specific recognition aptamer. The biosensor was based on a glassy carbon electrode modified with graphene oxide and gold nanoparticles. Then, the aptamer ssDNA sequence could be linked to the electrode. Each assembly step was accompanied by changes to the electrochemical parameters. After incubation of the modified electrode with Salmonella, the electrochemical properties between the electrode and the electrolyte changed accordingly. The electrochemical impedance spectrum was measured to quantify the Salmonella. The results revealed that, when more Salmonella were added to the reaction system, the current between the electrode and electrolyte decreased; in other words, the impendence gradually increased. A detection limit as low as 3 cfu/mL was obtained. This novel method is specific and fast, and it has the potential for real sample detection.
沙门氏菌是与食物相关疾病的最常见病因之一。利用沙门氏菌特异性识别适体开发了一种用于检测沙门氏菌的电化学生物传感器。该生物传感器基于用氧化石墨烯和金纳米颗粒修饰的玻碳电极。然后，适体单链DNA序列可以连接到电极上。每个组装步骤都伴随着电化学参数的变化。在用沙门氏菌孵育修饰电极后，电极与电解质之间的电化学性质相应改变。测量电化学阻抗谱以定量沙门氏菌。结果表明，当向反应体系中加入更多沙门氏菌时，电极与电解质之间的电流降低；换句话说，阻抗逐渐增加。获得了低至3 cfu/mL的检测限。这种新方法具有特异性和快速性，具有实际样品检测的潜力。
