Entropy-driven strand displacement reaction for ultrasensitive detection of circulating tumor DNA based on upconversion and Fe3O4 nanocrystals

Early detection of cancer biomarkers applied in real-time disease diagnosis and therapies can increase the survival rate patients. Circulating tumor DNA (ctDNA) as a typical biomarker plays great role process monitoring, especially early diagnosis. Unfortunately, most ctDNA systems have not been widely used due to their low sensitivity, poor specificity, high cost. Herein, we developed an alternative system present levels by recording fluorescence signals containing upconversion nanoparticles (UCNPs), Fe3O4, entropy-driven strand displacement reaction. The method has practical sensitivity with wide linear range from 100 amol L?1 1 nmol limit 1.6 L?1. Furthermore, demonstrates application mouse blood serum samples meets requirements for rapid, sensitive, specific, economical cancers. Thus, this may potential clinical