Multispectral sensing of biological liquids with hollow-core microstructured optical fibres
Timur Ermatov, Roman E. Noskov, Andrey Machnev, Ivan Gnusov, Vsevolod S. Atkin, Ekaterina N. Lazareva, Sergey V. German, S. S. Kosolobov, Timofei S. Zatsepin, Olga V. Sergeeva, Julia S. Skibina, Pavel Ginzburg, Valery V. Tuchin, Pavlos G. Lagoudakis, Dmitry A. Gorin
Abstract
Abstract The state of the art in optical biosensing is focused on reaching high sensitivity at a single wavelength by using any type of optical resonance. This common strategy, however, disregards the promising possibility of simultaneous measurements of a bioanalyte’s refractive index over a broadband spectral domain. Here, we address this issue by introducing the approach of in-fibre multispectral optical sensing (IMOS). The operating principle relies on detecting changes in the transmission of a hollow-core microstructured optical fibre when a bioanalyte is streamed through it via liquid cells. IMOS offers a unique opportunity to measure the refractive index at 42 wavelengths, with a sensitivity up to ~3000 nm per refractive index unit (RIU) and a figure of merit reaching 99 RIU −1 in the visible and near-infra-red spectral ranges. We apply this technique to determine the concentration and refractive index dispersion for bovine serum albumin and show that the accuracy meets clinical needs.