Immunolabeling lanthanide nanoparticles for alpha-fetoprotein measurement and cancer cells counting with detection of ICP-MS

A novel approach for measurement of alpha-fetoprotein (AFP) was developed with the detection of inductively coupled plasma mass spectrometry (ICP-MS), where lanthanide nanoparticles (NaYF₄: Yb, Er) were employed as immunolabeling probes. Amino modified NaYF₄: Yb, Er nanoparticles were synthesized via the hydrothermal procedure, which was followed by conjugated with anti-AFP McAb (labeling, Ab₂) to specifically identify AFP as immunolabeling probes. ⁸⁹Y in immunolabeling probes was employed as an elemental tag for AFP measurement with ICP-MS, along with a linear range of 2-180 ng mL^-1, and a LOD of 0.44 ng mL^-1, human serum was employed to validate the approach. Cells imaging was accomplished with laser ablation (LA)-ICP-MS to confirm the combination of cancer cells and the probes. Furthermore, ⁸⁹Y of the probes were used as an elemental tag for cancer cells counting in clinical blood samples with time resolved (TRA)-ICP-MS, indicating the potential of lanthanide nanoparticles in clinical diagnosis.