Antibody-directed Synthesis of Catalytic Nanoclusters for Bioanalytical Assays.

Synthesis of atomic nanoclusters (NCs) using proteins as scaffold has attracted great attention. Usually the synthetic conditions for the synthesis of NCs stabilized with proteins require extreme pHs or temperature. These harsh reaction conditions cause the denaturation of the proteins and end up in the loss of their biological functions. Until now there are no examples of the use of antibodies as NCs stabilisers. In this work we present the first method for the synthesis of catalytic NCs that uses antibodies for the stabilization of NCs. Anti-BSA IgG was used as a model in order to demonstrate that it is possible to use an antibody as scaffold for the synthesis of semiconductor and metallic NCs with catalytic properties. The synthesis of antibodies modified with NCs is carried out under non denaturing conditions, which do not affect the antibody structure. The resulting antibodies still maintain the affinity for target antigens and protein G. The catalytic properties of the anti-BSA IgG modified with NCs can be used to the quantification of BSA in a direct sandwich ELISA.