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.