Carbon nanotubes in electrochemical, colorimetric, and fluorimetric immunosensors and immunoassays: a review.

This review (with 126 references) summarizes the progress that has been made in the use of carbon nanotubes (CNTs) in immunoassays and immunosensors. Following an introduction into the field, a first large section covers functional group-modified CNTs as carriers for antibodies (with subsections on CNTs modified with amino, carboxy and by various other materials). The next section treats CNTs coupled with inorganic or organic materials as active components (with the use of nanoparticles such as Fe3O4, ZnO, gold) or with indium tin oxide (ITO), NiCoBP, ionic liquids, TiO2 nanosheets, metal clusters; chitosan, polystyrene, polydopamine, graphene, or enzymes. Another section discusses the synergistic effects of CNTs with metals, metal ions, and organic/inorganic materials. Several Tables are presented that give an overview on the wealth of methods and materials. A concluding section summarizes the current status, addresses current challenges, and gives an outlook on potential future trends. Graphical abstract Schematic presentation of the roles of carbon nanotubes (CNTs) in immunosensors and immunoassays. (I) Functional group-modified CNTs as carriers for antibody; (II) CNTs coupled with metal or organic materials as active component; and (III) Synergistic effects of CNTs with other materials to improve the parameters of immunosensors.