An Electrochemical Aptasensor For Detection of Helicobacter pylori Based on AuNPs and AgNPs-GO Nanoparticles

Xiaojuan You^1*Mingyi Shao^2*Huadong Wang³Rui Zhu¹Xinwei Liu¹Lei Dong⁴Yuesheng Gong^4*Yongwei Li^1*

• ¹The Second Clinical Medical College, Henan University of Traditional Chinese Medicine, Zhengzhou, China
• ²The First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou, China
• ³Henan Center for Drug Evaluation and Inspection, Zhengzhou, Henan Province, China
• ⁴Zhengzhou Anorectal Hospital, zhengzhou, China

Helicobacter pylori (H. pylori) is one of the main causes of gastritis and gastric ulcer. Early detection of H. pylori is of great significance for the prevention of gastric cancer. Herein, a sensitive electrochemical aptasensor using AgNPs-GO as redox probes was established for the specific detection of H. pylori in blood serum and stool samples. Firstly, AgNPs-GO nanocomposites were obtained by in-situ reduction of AgNPs on graphene oxide (GO) surface with glucose as reducing agent, in which AgNPs showed good biocompatibility and chemical stability, as well as redox property, and GO provided a large surface area to assemble a large number of AgNPs.Subsequently, the electrodeposition of AuNPs further improved the conductivity of the aptasensor. Additionally, the streptavidin was introduced into the aptasensor to effectively bind the biotin-modified aptamers. In this way, aptamers could be tethered to the surface through SA-biotin linkage, and H. pylori was selectivly binded by the aptamers subsequently. Under optimal conditions, the aptasensor could detect H. pylori in a wide concentration range (10 1 CFU mL -1 -10 8 CFU mL -1 ) with a low detection limit of 3 CFU mL -1 . What's more, the developed method showed excellent performance in practical application, which provided a promising possibility for the detection of other pathogens in clinical diagnosis.