Quantitative Detection of Procalcitonin with High Sensitivity, Specificity and Speed Based on SERS Magnetic Immunoassay

Procalcitonin (PCT), as a disease biomarker, is of significant importance in the early diagnosis of sepsis. To this end, we developed a surface-enhanced Raman scattering (SERS) magnetic immunoassay that utilizes the double-antibody sandwich principle for the rapid and quantitative detection of PCT. The core-shell nanoparticles which contain Raman reporters (Au@XP013@AgNPs) are paired with tracer antibodies and coupled with biotin-coupled capture antibodies, thereby forming a sandwich structure. This structure is readily captured by streptavidin (SA) magnetic beads and can be enriched by an external magnetic field. Raman spectroscopy was utilized to carry out detection, with PCT concentration ranging from 0-20 ng/mL. The Raman signal displays an excellent linear correlation with PCT concentration, and the LOD is 0.012 ng/mL, implying remarkable sensitivity. Efficiency of separation can be significantly enhanced by utilizing an external magnetic field, leading to a detection time of approximately 15 minutes. Thus providing a new technological reference for the clinical detection of sepsis biomarkers. A surface-enhanced Raman scattering magnetic immunoassay that utilizes the double-antibody sandwich principle for the rapid and quantitative detection of Procalcitonin. Simultaneous capture with dual antibodies guarantees high specificity. The sandwich structure was rapidly captured using SA magnetic beads, enriched through an external magnetic field, dramatically reducing the time required for detection.+image