On-chip structure-switching aptamer-modified magnetic nanobeads for the continuous monitoring of interferon-gamma ex vivo

Guozhen Liu*, Chaomin Cao, Shengnan Ni, Shilun Feng, Hui Wei

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)
13 Downloads (Pure)

Abstract

Cytokines are cell signaling molecules that indicate the health status of the body. In this study, we developed a microfluidic device integrated with structure-switching aptamers capable of continuously tracking the concentration of the cytokine interferon gamma (IFN-γ) in cell culture medium and blood serum. First, a ferrocene (Fc)-labeled structure-switching signaling aptamer with a hairpin structure targeting IFN-γ was immobilized on magnetic nanobeads by the strongest noncovalent interactions between streptavidin and biotin. The aptamer-modified magnetic nanobeads were trapped on a customized microfluidic chip by a magnetic field to form the sensing interface. The binding of IFN-γ could trigger the hairpin structure of the aptamer to unfold, pushing Fc redox molecules away from the sensing interface and consequently switching off the electrochemical signal. The change in the redox current of Fc was quantitatively related to the concentration of IFN-γ in a linear range of 10–500 pg mL−1 and with the lowest detection limit of 6 pg mL−1. This microfluidic device was specific to IFN-γ in the presence of overabundant serum proteins and allowed the continuous monitoring of IFN-γ without adding exogenous reagents. It provided a universal point-of-care biosensing platform for the real-time detection of a spectrum of analytes.

Original languageEnglish
Article number35
Pages (from-to)1-11
Number of pages11
JournalMicrosystems and Nanoengineering
Volume5
DOIs
Publication statusPublished - 26 Aug 2019

Bibliographical note

Copyright the Author(s) 2019. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

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