Biofunctionalized antibodies refer to proteins that are produced by the body as a result of antigen stimulation and have protective effects. It is a large Y-shaped protein secreted by plasma cells (effector B cells) and used by the immune system to identify and neutralize foreign substances such as bacteria and viruses. It is found only in the blood and other body fluids of vertebrates, and on the surface of the cell membrane of B cells. Antibodies recognize a unique feature of a particular foreign object, called an antigen.