Lately, gold nanoparticles in particular have been used in immunoassay based biosensors because of their good biological compatibility, excellent conducting capability, and high surface-to-volume ratio (Guo and Wang, 2007). On electrodes, gold nanoparticles (AuNPs) have the
5
ability to amplify the detection signal, improve the electron transducer, and reduce the detection limit in electrochemical biosensors