Quantitative determination of carbohydrate antigen 153 (CA153) in human serum plays an important role in early diagnosis of breast cancer.In this work, a highly sensitive and selective biosensor for CA153 detection was developed based on a fluorescent resonance energy transfer (FRET) strategy, Brushes in which near-infrared (NIR)-excitable upconversion nanoparticles (UCNPs) and the commercial organic dye, FAM, were employed as energy donor and energy acceptor, respectively.The two components were linked by a molecular beacon (MB) containing CA153 aptamer sequence and the upconversion fluorescence (UCF) of UCNPs can be effectively SLIP VIT C DRY OIL quenched by FAM.In presence of CA153, the hairpin structure was opened, resulting in the separation of UCNPs and FAM and the inhibition of FRET.
The UCF showed a linear relationship with the logarithm of CA153 concentration in the range from 0.01 to 150 U/mL, with a LOD of 4.5 mU/mL in HEPES buffer.This probe can be successfully applied for CA153 assay in human serum, which may be a useful tool for early diagnosis of breast cancer.