Figure 2.

(a) Capture antibodies affixed to a substrate capture antigen present in the analytical sample. Reporter antibodies, which are labeled with a reporter species such as a fluorophore or radioisotope, bind the captured antigen. (b) One possible sensor array based on immunoassays, in which the fluorophores tagging the reporter antibody are excited by laser and the PL read out on a CCD imaging array. The grid setup allows for multiplexing. (c) Fluorescence response to the presence of various analytes detected by immunoassays, including two types of BoNT (black and gray squares), ricin (open circles), and cholera toxin (open triangles). Reproduced with permission from [37].