Publication details
Conjugates of photon-upconversion nanoparticles with antibodies for immunochemical detection of tumor biomarkers
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| Year of publication | 2024 |
| Type | Conference abstract |
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| Description | Sensitive detection of clinical biomarkers is crucial for accurate identification of numerous illnesses. High sensitivity is especially important in the case of tumor diseases, allowing for early-stage cancer diagnosis and assessing treatment response. Due to the high specificity conferred by antibodies, immunochemical assays are often used for this purpose. However, conventional immunoassay labels, such as enzymes and fluorophores, often provide insufficient sensitivity for the detection of low-abundance biomarkers. Therefore, various kinds of nanoparticles have been investigated as labels to enhance immunoassay sensitivity. 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 luminescent properties can be tuned by altering the composition of dopant ions. The heterogeneous immunoassay format is typically predominant due to its high sensitivity and specificity. However, it requires immobilization and washing steps, leading to a prolonged procedure. In contrast, even though homogeneous immunoassays omit these time-consuming steps, they come at the cost of reduced specificity and sensitivity. To overcome these drawbacks, we have developed a novel homogeneous immunoassay format 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 successfully applied MPS in assays for prostate specific antigen and protein p53, two important tumor biomarkers. Such an immunoassay format was utilized for the first time, showing a strong potential to become a convenient, high-throughput bioanalytical method. |