A label-free DNA aptamer-based impedance biosensor for the detection of E. coli outer membrane proteins

Raquel B. Queiros, N. de-los-santos-Alvarez, João Paulo da Costa de Noronha, M. Goreti F Sales

Research output: Contribution to journalArticlepeer-review

61 Citations (Scopus)

Abstract

A label-free DNA aptamer-based impedance biosensor for the detection of E. coli outer membrane proteins (OMPs) was developed. Two single stranded DNA sequences were tested as recognition elements and compared. The aptamer capture probes were immobilized, with and without 6-mercapto-1-hexanol (MCH) on a gold electrode. Each step of the modification process was characterized by Faradaic impedance spectroscopy (FIS). A linear relationship between the electron-transfer resistance (R-et) and E. coli OMPs concentration was demonstrated in a dynamic detection range of 1 x 10(-7)-2 x 10(-6) M. Moreover, the aptasensor showed selectivity despite the presence of other possible water contaminates and could be regenerated under low pH condition. The developed biosensor shows great potential to be incorporated in a biochip and used for in situ detection of E. coli OMPs in water samples. (c) 2013 Elsevier B.V. All rights reserved.
Original languageEnglish
Pages (from-to)766-772
JournalSensors And Actuators B-Chemical
Volume181
DOIs
Publication statusPublished - May 2013

Keywords

  • Aptamer
  • Biosensor
  • DNA
  • E. coli
  • Faradaic impedance spectroscopy
  • OMPs

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