“…On such a basis, much attention has been devoted to developing procedures to detect the presence of CA 15-3 protein at very low concentrations in a physiological environment and biological uids. 8 Currently, detection of the CA 15-3 biomarker is oen carried out using immunoassays that employ various signal transduction approaches, such as ELISA, 10,11 ow uorescence, 12 chemiluminescence, 13,14 electrochemiluminescence, 15,16 and electrochemistry. 17,18 Although these biosensors are highly selective due to the use of corresponding natural biomolecules such as enzymes, antibodies, aptamers, and lectins, they oen present problems of high cost, tendency to denature, and low abundance.…”