Background-free detection of prostate-specific antigen utilizing an immunomagnetic assay with upconversion nanoparticles
| Autoři | |
|---|---|
| Rok publikování | 2024 |
| Druh | Konferenční abstrakty |
| Fakulta / Pracoviště MU | |
| Citace | |
| Popis | Prostatic carcinoma is a severe oncologic disease that can be diagnosed via the immunochemical detection of its most important biomarker, the prostate-specific antigen (PSA). Blood serum concentration of PSA up to 2.5 ng/mL is considered normal and can be generally detected by conventional techniques, such as the enzyme-linked immunosorbent assay (ELISA). However, more sensitive approaches are necessary for early-stage diagnosis and minor changes monitoring. Photon-upconversion nanoparticles (UCNPs) are lanthanide-doped nanocrystals that exhibit anti-Stokes luminescence, thus omitting optical background interference and enhancing detection sensitivity. It is possible to utilize them as sensitive immunoassay labels in, e.g., the microtiter plate upconversion-linked immunosorbent assay (ULISA). However, even the sensitivity of the ULISA may not sufficient for the detection of extremely low-abundant analytes. Magnetic microparticles (MBs) are a promising alternative solid phase for microtiter plate immunoassays, allowing for analyte preconcentration and improving the assay sensitivity. We have developed and optimized a sandwich immunoassay for the detection of PSA based on MBs and UCNPs. We conjugated a monoclonal anti-PSA antibody to MBs and a polyclonal one to UCNPs via streptavidin-biotin binding and tested their functionality. Optimal concentrations of MBs and serum were selected, followed by the fully optimized analysis of model samples of spiked serum. The assay in serum reached an LOD of 11.1 pg/mL, comparable to an ELISA using identical immunoreagents. An additional magnetic preconcentration step further improved the LOD to 0.25 pg/mL, which was 3-fold better than ELISA and 44-fold better than MB-based ELISA using identical immunoreagents. The developed technique was then performed in clinical sample analysis, demonstrating the potential of using MBs combined with UCNPs for the sensitive detection of cancer biomarkers. Moreover, we are currently aiming to optimize the method to reach ultrasensitive single-molecule detection in a microfluidic setup as a means to enhance the sensitivity further. |
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