Up-conversion fluorescence biosensor for sensitive detection of CA-125 tumor markers

Sensitive and specific bioassays of tumor markers are critical for early cancer detection and treatment. In recent years, lanthanide (Ln3+) doped upconversion nanoparticles (UCNPs) have attracted wide attentions in tumor markers detection. Herein, we combined NaYF4:Yb,Tm and silver nanoparticles, serving as energy donor and receptor, respectively, to form an up-conversion fluorescence based inhibitory tumor marker biosensor system. The tumor marker CA-125 molecules are labeled with silver NPs, and the energy transfer fluorescent signal can be detected between the UCNPs and the silver NP receptors. The biosensor shows good stability, high sensitivity and selectivity in the tumor marker concentration range from 5 to 100 ng/mL, as well as a detection limit of 120 pg/mL. Due to the advantage of ease of fabrication and operation, low cost and high information capacity, this technology holds great potential for the clinical applications.