Publication details
Bioconjugates of upconversion nanoparticles for cancer biomarker detection
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| Year of publication | 2025 |
| Type | Conference abstract |
| Citation | |
| Description | Sensitive detection of clinical biomarkers is crucial for the diagnosis of numerous illnesses. High sensitivity is of the utmost importance in the case of cancer biomarkers, as monitoring slight changes in their concentrations allows for early-stage cancer diagnosis and the assessment of treatment response. Due to their high specificity conferred by antibodies, immunochemical assays have proven indispensable for biomarker detection. However, conventional immunoassay labels, such as enzymes or fluorophores, are typically not sensitive enough for the detection of low-abundance cancer biomarkers. To enhance sensitivity, various kinds of nanoparticles are often employed as labels. Photon-upconversion nanoparticles (UCNPs) stand out as one of the most promising options. These lanthanide-doped nanocrystals can convert near-infrared radiation into light of a shorter wavelength (anti-Stokes emission), significantly reducing the optical background. Moreover, their emission spectra can be easily tuned by altering the composition of dopant ions. In immunoassays, the heterogeneous assay format is typically preferred due to its high specificity and sensitivity. These desirable properties are ensured by immobilization and washing steps, which significantly prolong the procedure. On the other hand, homogeneous immunoassays omit these time-consuming steps; however, this comes at the cost of reduced specificity and sensitivity. To combine the advantages of each assay format, we have developed a novel artificial intelligence-aided homogeneous immunoassay based on massively parallel spectroscopy (MPS). This single-molecule method utilizes two different UCNP–antibody labels with distinct emission spectra binding to the analyte molecule; only sandwich immunocomplexes containing the analyte molecule and both labels are detected. We have successfully employed MPS in assays for prostate-specific antigen and protein p53, two important cancer biomarkers. This immunoassay format was utilized for the first time, showing strong potential to become a convenient and high-throughput method for biomarker detection. |