Enhanced gold nanoparticle based ELISA for a breast cancer biomarker.

In this work, we developed an optical enzyme-linked immunosorbent assay (ELISA) immunoassay for the analysis of CA15-3 antigen, an important biomarker present in blood samples and useful for the follow-up of the medical treatment of breast cancer. Gold nanoparticles (AuNPs) were used as carriers of the signaling antibody anti-CA15-3-HRP (horseradish peroxidase) in order to achieve an amplification of the optical signal. In the range between 0 and 60 U/mL, the assay adopting AuNPs as an enhancer resulted in higher sensitivity and shorter assay time when compared to classical ELISA procedures. The application of AuNPs to the commercially available ELISA test can be useful to improve important immunoanalysis procedures where a more confident result is needed.