Nanowire Aptasensors for Electrochemical Detection of Cell-Secreted Cytokines

Published

October 9, 2017

Author(s)

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

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 aptamer-based electrochemical biosensor for rapid and sensitive detection of IFN-γ. In this study, we explored the use of silicon nanowires (Si 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 3x faster and were 2x 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 co-infected with HIV/TB.

Citation

ACS Sensors

Volume

2

Issue

11

Pub Type

Journals

Citation

Liu, Y. , Rahimian, A. , Krylyuk, S. , Vu, T. , Crulhas, B. , Stybayeva, G. , Shin, D. , Davydov, A. , Revzin, A. and Imanbekova, M. (2017), Nanowire Aptasensors for Electrochemical Detection of Cell-Secreted Cytokines, ACS Sensors (Accessed November 28, 2024)