食品科学 ›› 2021, Vol. 42 ›› Issue (18): 284-291.doi: 10.7506/spkx1002-6630-20200910-113

• 安全检测 • 上一篇    下一篇

基于还原氧化石墨烯/碳纳米管-纳米金复合纳米材料的阻抗型电化学适配体传感器检测铜绿假单胞菌

贾飞,闫文杰,戴瑞彤,刘毅,李兴民   

  1. (1.中国农业大学食品科学与营养工程学院,北京 100083;2.北京联合大学生物化学工程学院,北京 100023)
  • 发布日期:2021-09-29
  • 基金资助:
    现代农业产业技术体系北京市家禽创新团队项目(BAIC04-2020)

An Impedimetric Aptasensor Based on Reduced Graphene Oxide/Carbon Nanotube-Gold Nanoparticles Nanocomposite for the Detection of Pseudomonas aeruginosa

JIA Fei, YAN Wenjie, DAI Ruitong, LIU Yi, LI Xingmin   

  1. (1. College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; 2. College of Biochemical Engineering, Beijing Union University, Beijing 100023, China)
  • Published:2021-09-29

摘要: 基于还原氧化石墨烯/碳纳米管-纳米金复合纳米材料制备电化学阻抗传感器检测铜绿假单胞菌。采用电化学沉积的方法将氧化石墨烯/碳纳米管修饰在电极表面,并将氧化石墨烯电化学还原。随后将纳米金沉积在电极表面,最后将巯基修饰的铜绿假单胞菌适配体通过金硫共价键结合在纳米金表面,制成工作电极。用扫描电镜观察合成的还原氧化石墨烯/碳纳米管-纳米金材料的形貌。用循环伏安法对组装电极的每一步进行电化学表征。当铜绿假单胞菌在适配体修饰的电极表面孵育后,适配体会将目标菌捕获在电极表面,阻碍电极表面电子传输,导致阻值上升,根据电阻变化值可实现对目标菌的定量检测,检测线性范围为10~106 CFU/mL,检出限可达4 CFU/mL,本实验方法是已知的检测铜绿假单胞菌灵敏度最高的电化学方法。

关键词: 电化学阻抗;适配体传感器;铜绿假单胞菌;还原氧化石墨烯;碳纳米管;纳米金

Abstract: An impedimetric aptasensor based on reduced graphene oxide (rGO)/carbon nanotube (CNT)-gold nanoparticles (AuNPs) nanocomposite was prepared for the detection of Pseudomonas aeruginosa. The GO/CNT was modified on the surface of the electrode by electrodeposition, followed by electrochemicalreduction of GO. Then, electrodeposition was used to deposit AuNPs on the surface of the electrode. The working electrode was prepared by bonding thiol-modified aptamer specific for P. aeruginosa to the AuNPs composite via Au-S bonds. The morphology of the rGO/CNT-AuNPs nanocomposite was characterized by scanning electron microscopy. Cyclic voltammetry was used to monitor each assembly step. When exposed to samples containing P. aeruginosa, the anti-P. aeruginosa aptamer on the electrode could capture its target, blocking electron transport and consequently resulting in a great increase in impedance. P. aeruginosa could be quantified by the change in impedance. The linear range of this method was 10–106 CFU/mL and the detection limit was 4 CFU/mL. To the best of our knowledge, the developed electrochemical biosensor may be the most sensitive detection method for P. aeruginosa.

Key words: electrochemical impedance; aptasensor; Pseudomonas aeruginosa; reduced graphene oxide; carbon nanotube; gold nanoparticles

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