Combined detection of breast cancer biomarkers based on plasmonic sensor of gold nanorods

In this study, a combined detection assay for determination of cancer antigen 15-3 (CA15-3) and copper level in breast cancer serum was developed by use of gold nanorod (GNR)-based plasmonic sensor. Rapid detection of tumor marker (CA15-3) can be accomplished through a simple transduction of optical signal induced by immune-reaction between CA15-3 and GNR@CA15-3 antibody. On the other hand, the copper-induced change of localized surface plasmon resonance of GNRs results in a direct readout of optical signal. Therefore, practical application for combined determination of CA15-3 and copper levels of human serum samples of breast cancer was performed. The results are close agreement with those given by the hospital or other standard approach, confirming this assay with high accuracy. The combined detection strategy provides potential applications for early diagnosing and monitoring the progress of malignant tumor.