Nanowire Aptasensors for Electrochemical Detection of Cell-Secreted Cytokines

ACS Sensors (2017)
Ying Liu, Ali Rahimian, Sergiy Krylyuk, Tam Vu, Bruno Crulhas, Gulnaz Stybayeva, Meruyert Imanbekova, Dong-Sik Shin, Albert Davydov, and Alexander Revzin
First online: 9 October 2017
DOI: 10.1021/acssensors.7b00486

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.

 

KEYWORDS:

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

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О нас

Республиканское государственное предприятие «Национальный центр биотехнологии» Комитета науки Министерства образования и науки Республики Казахстан – ведущий биологический научный центр страны, реализующий государственную политику поддержки и развития биотехнологической отрасли - создан Указом Президента Республики Казахстан в 1993 г.

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