Sensitive cytokine assay based on optical fiber allowing localized and spatially resolved detection of interleukin-6

Guozhen Liu*, Kaixin Zhang, Annemarie Nadort, Mark R. Hutchinson, Ewa M. Goldys

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

38 Citations (Scopus)
109 Downloads (Pure)


We demonstrated a cytokine detection device based on gold nanoparticle modified silica optical fiber for the monitoring of locally variable cytokine interleukin-6 (IL-6) concentrations using a sandwich immunoassay scheme. The fiber is designed to be introduced into an intrathecal catheter with micrometer-sized holes drilled along its length to enable fluid exchange between the outside and inside of the catheter. An exposed optical fiber (diameter 125 μm) modified with a layer of gold nanoparticles was functionalized with the IL-6 capture antibody to form the sensing interface. The immunocapture device was incubated with a cytokine solution to capture the analyte. The device was then exposed to the IL-6 detection antibody which was loaded on the fluorescently labeled magnetic nanoparticles, making it possible to quantify the cytokine concentration based on the intensity of fluorescence. A reliable method for quantifying the fluorescent signal on a 3D structure was developed. This device was applied to the detection of cytokine IL-6 with the low limit of detection of 1 pg mL-1 in a sample volume of 1 μL. The device has the linear detection range of 1-400 pg mL-1 and spatial resolution on the order of 200-450 μm, and it is capable of detecting localized IL-6 secreted by live BV2 cells following their liposaccharide stimulation. This biological detection system is suitable for monitoring multiple health conditions.

Original languageEnglish
Pages (from-to)218-226
Number of pages9
JournalACS Sensors
Issue number2
Publication statusPublished - 24 Feb 2017

Bibliographical note

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.


  • optical fiber
  • cytokines
  • localized and spatially resolved detection
  • IL-6
  • immunosensors
  • cytokine test strip


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