 This study focused on developing two biosensors for detecting breast cancer biomarkers, her one and her two. The biosensors utilized gold chip technology and amperometric detection of the enzyme horseradish peroxidase, HRP, which was labeled with antibodies against the biomarker. The biosensors were able to detect levels of the biomarkers in both buffer and serum samples at concentrations below the clinically relevant range. Additionally, the researchers found that the use of gold nanoparticles increased the sensitivity of the assay and enabled detection of lower levels of the biomarkers. This study demonstrates the potential of these biosensors for early detection and monitoring of breast cancer. This article was authored by Shailini Wignaraja, Aiva Cayonella, and it is in E. Todd Hill.