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.

光学生物传感领域的最新技术集中于通过使用任何类型的光学共振在单一波长下达到高灵敏度。然而，这种常见策略忽视了在宽带光谱域上同时测量生物分析物折射率的有希望的可能性。在这里，我们通过介绍光纤内多光谱光学传感（IMOS）的方法来解决这个问题。其工作原理依赖于检测当生物分析物通过液体细胞流过空心微结构光纤时传输的变化。IMOS 提供了一个独特的机会来测量 42 个波长的折射率，每个折射率单位 (RIU) 的灵敏度高达 ~3000 nm ，在可见光和近红外光谱范围内品质因数达到 99 RIU ^-1。我们应用该技术测定牛血清白蛋白的浓度和折射率色散，结果表明其准确性满足临床需求。