New research from CNBP scientists reports on a cytokine sensor – fabricated on the surface of an optical fibre. Cytokines are molecules that play a critical role in cellular response to infection, inflammation, trauma and disease. Lead author on the paper, published in the journal ‘Biosensors and Bioelectronics’, is Centre PhD student Kaixin Zhang who is based at Macquarie University.
Journal: Biosensors and Bioelectronics.
Authors: Kaixin Zhang, Guozhen Liu, Ewa M. Goldys.
Abstract: Detection of a very low amount of cytokines such as interleukin-6 (IL-6) in clinical fluids is important in biomedical research and clinical applications. Here, we demonstrate spatially-localised ultrasensitive (femtogram mL−1) level detection of IL-6 in serum and in cell culture media. Our approach is based on a sandwich immunosensor fabricated on the surface of an optical fibre. Firstly, the biotinylated IL-6 capture antibody was immobilized on the fibre surface by biotin-streptavidin coupling. Then the fabricated fibre was used for capturing IL-6 followed by exposure to detection antibody which was labeled with the fluorescent magnetic nanoparticles to report the signal. A linear relationship between IL-6 concentration and the fluorescence signal was obtained in the range from 0.4 pg mL−1 to 400 pg mL−1 of IL-6, with the limit of detection down to 0.1 pg mL−1. In addition, this optical fibre sensor was successfully applied for the localized detection of IL-6 with the spatial resolution of 200 µm and a sample volume of 1 μL. Finally, the performance of the fibre sensor was demonstrated by detection of IL-6 secreted by BV-2 cells with comparable performance of the conventional enzyme-linked immunosorbent assay (ELISA).