Multispectral sensing of biological liquids with hollow-core microstructured optical fibres

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. Optical biosensing: analyzing biological fluids at many wavelengths In-fibre multispectral optical sensing (IMOS) can detect and analyze the optical properties of biological liquids at multiple wavelengths simultaneously, using hollow-core microstructured optical fibres (HC-MOFs). Researchers in Russia and Israel, led by Dmitry Gorin at the Skolkovo Institute of Science and Technology in Moscow and Roman Noskov at Tel Aviv University, developed IMOS and demonstrated its potential using solutions of the bovin serum albumin. IMOS detects changes in the transmission of light in the fibre when the fluid being analyzed flows through the fibre’s hollow core. Refractive index values were measured at 42 wavelength’s of visible and near-infra-red light simultaneously, with potential to measure many more. IMOS is sufficiently accurate for clinical analysis, including detecting the presence and concentration of specific biomolecules in blood. The procedure could supply immediate diagnostic results relevant to a variety of medical conditions, including diabetes and cancer.