Detection of three tumor biomarkers in human lung cancer serum using single particle inductively coupled plasma mass spectrometry combined with magnetic immunoassay

A new method for simultaneously determining cytokeratin fragment antigen 21-1 (CYFRA21-1), carcinoembryonic antigen (CEA), and carbohydrate antigen (CA15-3) was developed using single-particle, ICP-MS-based, magnetic immunoassay. Gold nanoparticles (AuNPs), ZnSe quantum dots (QDs), and Silver nanoparticles (AgNPs) were employed to tag antibodies. A highly efficient capture of CYFRA21-1, CEA, and CA15-3 was achieved using biotinylated, antibody-coated magnetic beads. AuNPs/ZnSe QDs/AgNPs-tagged second antibodies helped realize sensitive quantification of the target antigen using single particle ICP-MS. Under optimum conditions, CYFRA21-1, CEA, and CA15-3 linear concentration ranges were 0.05-50 ng mL(-1), 0.02-100 ng mL(-1), and 0.6-250 mU mL(-1). The correlation coefficients were 0.9999, 0.9987, and 0.9970, respectively. CYFRA21-1, CEA, and CA15-3 detection limits were 0.02 ng mL(-1), 0.006 ng mL(-1), and 0.25 mU mL(-1), respectively. Relative standard deviations (RSD) for CYFRA21-1, CEA, and CA15-3 were 3.2%, 4.4%, and 4.2%, respectively. The method simultaneously detected CYFRA21-1, CEA, and CA15-3 in human lung cancer serum samples with recoveries of between 89.8% and 101%.