Multianalysis of Thyroid Tumor Markers on the Surface of a Porous Membrane and Semiconductor Substrates using Gold Nanoparticles as a Label

We present a method for the simultaneous detection of thyroglobulin and thyroid-stimulating hormone on microchips using gold nanoparticles for antibody labeling. Nitrocellulose and silicon were used as supports for the microchips. The detection principle was based on a sandwich immunoassay using a pair of antibodies that simultaneously bind to the analyte. Specific monoclonal antibodies that are most sensitive and specific in detecting the hormones and signal-to-background ratio are selected. The analytical signal was the intensity of the staining of the microchip zones on the membrane and the nanoparticle density on the silicon substrate. The detection limit for thyroglobulin and thyroid-stimulating hormone was 0.25 ng/mL and 0.016 μIU/mL for the membrane support and 0.1 ng/mL and 0.013 μIU/mL for silicon substrate, respectively. The method can be further used to develop nanoscale sensor devices for the express diagnostics of thyroid pathologies.