Photon-upconversion nanoparticles as a background-free label in lateral flow immunoassays
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| Year of publication | 2021 |
| Type | Conference abstract |
| MU Faculty or unit | |
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| Description | Sensitive detection of clinically important analytes is critical for early disease diagnosis and initiation of treatment. Immunochemical assays are widely used to determine the concentration of analytes in complex samples due to the high specificity provided by antibodies. Lateral flow immunoassays (LFIAs) belong among the most popular forms of immunoassays. They are based on nitrocellulose membranes, and the most significant advantage of this approach is that there is no need for laboratory equipment to perform the assay. Most LFIAs are based on gold nanoparticles that allow naked-eye readout. However, the recent progress in nanotechnology provided various other nanomaterials that can be used as alternative labels. Our work focused on photon-upconversion nanoparticles (UCNPs), which exhibit anti-Stokes luminescence, meaning they can be excited by the NIR laser and detected in the Vis region without optical background interference. In our proof-of-principle assay, we detected biotinylated bovine serum albumin using streptavidin-coated UCNPs. The testing of different nitrocellulose membranes revealed that FF120HP Plus Thick provides the highest signal-to-background ratio, making it the most suitable for the development of the final LFIA kit. We have also highlighted the necessity of suitable blocking conditions to prevent non-specific binding; the best results were achieved with 50% SuperBlock with 0,05% Tween 20. The signal-to-background ratio of the optimized assay reached up to 290, demonstrating the potential of UCNPs as labels in LFIAs. |
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