Nanowire Aptasensors for Electrochemical Detection of Cell-Secreted Cytokines

Ying Liu, Ali Rahimian, Sergiy Krylyuk, Tam Vu, Bruno Crulhas, Gulnaz Stybayeva, Meruyert Imanbekova, Dong Sik Shin, Albert Davydov, Alexander Revzin

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

Cytokines are small proteins secreted by immune cells in response to pathogens/infections; therefore, these proteins can be used in diagnosing infectious diseases. For example, release of a cytokine interferon (IFN)-γ from T-cells is used for blood-based diagnosis of tuberculosis (TB). Our lab has previously developed an atpamer-based electrochemical biosensor for rapid and sensitive detection of IFN-γ. In this study, we explored the use of silicon nanowires (NWs) as a way to create nanostructured electrodes with enhanced sensitivity for IFN-γ. Si NWs were covered with gold and were further functionalized with thiolated aptamers specific for IFN-γ. Aptamer molecules were designed to form a hairpin and in addition to terminal thiol groups contained redox reporter molecules methylene blue. Binding of analyte to aptamer-modified NWs (termed here nanowire aptasensors) inhibited electron transfer from redox reporters to the electrode and caused electrochemical redox signal to decrease. In a series of experiments we demonstrate that NW aptasensors responded 3× faster and were 2× more sensitive to IFN-γ compared to standard flat electrodes. Most significantly, NW aptasensors allowed detection of IFN-γ from as few as 150 T-cells/mL while ELISA did not pick up signal from the same number of cells. One of the challenges faced by ELISA-based TB diagnostics is poor performance in patients whose T-cell numbers are low, typically HIV patients. Therefore, NW aptasensors developed here may be used in the future for more sensitive monitoring of IFN-γ responses in patients coinfected with HIV/TB.

Original languageEnglish (US)
Pages (from-to)1644-1652
Number of pages9
JournalACS Sensors
Volume2
Issue number11
DOIs
StatePublished - Nov 22 2017

Keywords

  • IFN-γ aptamer
  • aptasensor
  • electrochemical biosensor
  • nanowire electrode
  • tuberculosis detection

ASJC Scopus subject areas

  • Bioengineering
  • Instrumentation
  • Process Chemistry and Technology
  • Fluid Flow and Transfer Processes

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