Figure 15.

(A) Schematic diagram for the stepwise assembly of an electrochemical immunosensor for prostate-specific antigen (PSA) operating in the signal amplification strategy using a glassy carbon electrode (GCE) successively covered with gold nanoparticles (AuNPs) deposited onto flower-like SnO₂ anchored with palladium NPs (Pd@SnO₂), Ab₁ antibody, ovalbumin (OVA), the PSA target, and the bioconjugate in the form of CMK-3 with AuNPs, horseradish peroxidase (HRP) and methylene blue (MB) (reproduced from [256]). (B) Fabrication procedure for penicillin binding protein 2 a (PbP2a) immunosensor based on gold electrode covered with polyamidoamine (PAMAM), AuNPs decorated graphitized mesoporous carbon (GMC), protein A and Ab₁ antibody, the antigen (Ag) and the nanocarriers made of hollow gold nanospheres (HGNPs) incubated with the second antibody (Ab₂) and doxorubicin (Dox)(reproduced from [254]).