Interleukin (IL)-1β is a pivotal pro-inflammatory cytokine that plays a critical role in mediating inflammatory responses across various pathological conditions, including arthritis, gastritis, and tissue injury, where its expression levels are significantly elevated. The enzyme-linked immunosorbent assay (ELISA) remains the gold standard for IL-1β detection; however, conventional ELISA methods are time-consuming, labor-intensive, and heavily reliant on expensive monoclonal antibodies. Consequently, there is an urgent need to develop a rapid, sensitive, and cost-effective immunodetection strategy for IL-1β. Nanobodies (Nbs), due to their small molecular size, high stability, low production costs, and high-yield expression in microbial systems, have emerged as promising alternatives to conventional antibodies. Concurrently, quantum dots (QDs), as innovative inorganic fluorescent nanomaterials, exhibit exceptional optical properties, including broad excitation spectra, long fluorescence lifetimes, and superior photostability, rendering them highly advantageous for advanced immunoassay applications. In this study, we successfully screened and purified two specific Nbs targeting IL-1β, namely IL-1β-Nb44 and IL-1β-Nb47. We utilized water-soluble CdSe/ZnCdS QDs to label IL-1β-Nb47, which facilitated the development of a fluorescent probe (QDs–IL-1β-Nb47). By leveraging the specific recognition capabilities of this probe for the IL-1β antigen, we established three straightforward and cost-effective fluorescent-linked immunosorbent assay (FLISA) formats. The performance of these FLISA systems was systematically evaluated and compared in terms of sensitivity. Among the three developed FLISA platforms, the SA/Biotin-IL-1β-Nb44/ QDs–IL-1β-Nb47 system exhibited the highest sensitivity for IL-1β detection. The integration of nanobody-based recognition with QD fluorescence labeling significantly enhanced the sensitivity of the assay while maintaining operational simplicity and reducing overall costs. This study presents a rapid, sensitive, and cost-effective FLISA method for IL-1β leveraging Nbs and QDs. The proposed strategy establishes a robust technical foundation for future clinical diagnostic applications and holds significant potential for improving the monitoring and management of inflammation-related diseases.
Hou et al. (Tue,) studied this question.