In this study, we used a CdSe/ZnS core/shell quantum dot (QD) as a fluorescent probe and developed a quantum dot-based fluorescence-linked immunosorbent assay (QD-FLISA) to quantitatively determine procalcitonin (PCT) levels in samples. The QD-antibody probe had a high fluorescent intensity and excellent stability, which met the needs of commercial fluorescent probe materials. Due to the excellent properties of clinical testing for PCT, this QD-FLISA method showed tremendous potential for use in in vitro diagnostic (IVD) kits.