Fig. 3.

Multiprotein detection protocols using multiple labels or multiple electrodes. (a) Magnetic beads coated with differing primary antibodies are used to capture their corresponding antigens. Then, secondary antibodies labelled with differing inorganic nanocrystal tracers bind to the corresponding antigens. Following acid dissolution of the nanocrystals, the resulting ions are detected by electrochemical stripping. Adapted with permission from reference.⁵⁴ (b) Magnetic beads labelled with multi-enzymes and Ab₂ were used to capture specific analytes offline, and a sandwich immunoassay was performed on an 8-electrode array modified with different antibodies. (c) Multiplexed immunoassay using an array of screen printed carbon electrodes modified with different capture antibodies employing universal MWCNT bioconjugates. Adapted with permission from reference.⁵¹