Rapid detection of prostate cancer biomarkers in living cells and urine samples using diboronic acid fluorescent probe

Rapid and sensitive screening methods are critical for early-stage cancer diagnosis. Sialyl Lewis X (sLeX), a terminal O-glycan structure highly expressed on the surface of cancer cells, can be employed as a marker for cancer detection. In this study, a fluorescence analysis method based on a diboronic acid fluorescent (DBF) probe was established to detect the content of sLeX in solution under physiological conditions within 10 min and sLeX-carrying secreted proteins in prostate cancer cells within 15 min, with a limit of detection of 4.58 × 10−10 mol/L. Fluorescence microscopy imaging confirmed that proteins carrying sLeX were secreted from the cell into the extracellular space. Finally, urine samples from clinical patients (n = 15) and healthy volunteers (n = 5) were examined and analyzed using this method, and significant differences in sLeX levels between the two groups were found. In conclusion, we successfully established a method for detecting sLeX levels in urine samples of patients with prostate cancer using a DBF probe, which can be used to improve early non-invasive screening, disease development monitoring and prognostic detection of prostate cancer.