DNA-functionalized LnNP-MNP assemblies for dual-model sensing of alkaline phosphatase

Alkaline phosphatase (ALP) is a vital diagnostic indicator for hepatocellular carcinoma and bone diseases, which can convert the 5' phosphate groups of the DNA to the hydroxyl group (-OH). ALP sensing is of importance to clinical diagnosis of cancer. Herein, a dual-model sensing platform of ALP was developed by combining lanthanide-doped nanoparticles (LnNPs) and streptavidin magnetic nanoparticles (SA-MNPs) based on dissociation-enhanced photoluminescence (DEPL) and inductively coupled plasma mass spectrometry (ICP-MS). In this approach, LnNP-MNP assemblies were fabricated by hybridizing poly-C-modified LnNPs and poly-Gfunctionalized MNPs. ALP catalyzes 5' phosphate groups from poly-C transform into hydroxyl groups, causing the LnNPs to be stripped from LnNP-MNP assemblies. After magnetic separation, the DEPL intensity and ICP-MS intensity of LnNPs in the supernatant were measured to realize dual-model sensing of ALP. Significantly, the LnNP-MNP assemblies integrated the merit of non-fluorescence background and high mass spectrometric response of LnNPs, and excellent magnetic separation of MNPs, exhibiting reliable analytical performance for the sensing of ALP in human serum and cancer cells.