Local sensing of absolute refractive index during protein-binding using microlasers with spectral encoding
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Multiplexed, specific, and sensitive detection of antigens is critical for the rapid and accurate diagnosis of disease and the informed development of personalized treatment plans. Here, it is shown that polymer microsphere lasers can be used as photonic sensors to monitor and quantify direct surface binding of biomolecules via changes in the refractive index. The unique spectral signature of each individual laser can be used to find their size and effective refractive index which adds a new encoding dimension when compared to conventional fluorescent beads. Antibody-functionalized microlasers selectively detect protein binding, as demonstrated for Immunoglobulin G and C-reactive protein, and have the ability to resolve different stages of the multilayer surface modification. Moreover, by continuously monitoring single lasers, the possibility of real-time monitoring of binding dynamics between antigens in solution phase and the immobilized antibodies is demonstrated. For multiplexed detection, the microlasers are employed in a flow cytometer configuration, with fast spectral detection and identification of microlasers with and without antigen binding. It is envisioned that by combining microlasers with well-established surface modification chemistries and flow geometries, the multiplexing ability of microbead immunoassays can be strongly increased while also opening avenues for single-cell profiling within heterogeneous cell populations.
Caixeiro , S , Kunstmann-Olsen , C , Schubert , M , Hill , J S , Barnard , I R M , Simmons , M D , Johnson , S & Gather , M C 2023 , ' Local sensing of absolute refractive index during protein-binding using microlasers with spectral encoding ' , Advanced Optical Materials , vol. 11 , no. 13 , 2300530 . https://doi.org/10.1002/adom.202300530
Advanced Optical Materials
Copyright © 2023 The Authors. Advanced Optical Materials published by Wiley-VCH GmbH This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
DescriptionFunding: Engineering and Physical Sciences Research Council - EP/P030017/1; Alexander von Humboldt-Stiftung; European Research Council - 640012; Royal Society - DH160102.
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