A sensitive electrochemical aptasensor based on single wall carbon nanotube modified screen printed electrode for detection of Escherichia coli O157:H7

¹Research and Technology Center for Biomolecules, Ferdowsi University of Mashhad, Mashhad, Iran

²Department of Food Nanotechnology, Research Institute of Food Science and Technology (RIFST), Mashhad, Iran

³Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran

⁴Department of Biology, School of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran

⁵Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran 

Adv. Mater. Lett., 2018, 9 (5), pp 369-374

DOI: 10.5185/amlett.2018.1701

Publication Date (Web): May 17, 2018

Copyright © IAAM-VBRI Press

E-mail: elhamsheikhzadeh@yahoo.com

Abstract

Escherichia coli O157:H7 (E.coli O157:H7), is an extremely infectious and potentially fatal water and food-borne pathogen, responsible for numerous hospitalisations and deaths all over the world. Herein we reported the development of simple and label-free electrochemical aptasensor based on single wall carbon nanotube (SWCNT) modified screen printed electrode (SPE) to detect E.coli O157:H7 bacteria. The electrochemical probe of methylene blue (MB) was used to investigate the interactions between aptamer and E.coli O157:H7. The resulting MB/Apt/SWNT/SPE layer exhibited good current response to detect E.coli O157:H7. The aptasensor detect E.coli O157:H7 in the concentration range of 1.7×10¹ - 1.1×10⁷ CFU mL^-1 and limit of quantification of 1.7×10¹ CFU mL^-1. The proposed aptasensor is rapid, convenient and low-cost for effective sensing of E.coli O157:H7 with high selectivity over interference bacteria. The suitability of the aptasensor for real sample measurements was investigated by recovery studies in tap water sample. 

Keywords

Escherichia coli O157:H7, aptamer, electrochemical aptasensor, label-free detection.