Portable detection of serum HER-2 in breast cancer by a pressure-based platform

A high serum HER-2 extracellular domain (sHER-2 ECD) level has a reverse association with tumor behaviors. In this study, a portable platform for the disease biomarker sHER-2 ECD detection has been established using a pressure-based bioassay. The pressure bioassay consists of a monoclonal antibody immobilized on an eight-well strip, the analyte HER-2, and another monoclonal antibody labeled with the Pt nanoparticles (PtNPs), which have the catalytic ability to decompose H 2 O 2 into H 2 O and O 2 (g). The increased pressure due to O 2 (g) generation is measured by a hand-held pressure meter. A total of 34 serum samples were collected to validate the performance of the pressure bioassay. The results showed that the pressure bioassay platform of HER-2 had a dynamic range from 2 to 50 ng/mL with a limit of detection (LOD) of 2 ng/mL, which was consistent with the ELISA result. In the real serum samples, there was a significant correlation between sHER-2 ECD level and several clinicopathological parameters, especially tissue HER-2 status. Furthermore, the sHER-2 ECD level was found to decrease after targeted therapy in a patient with tHER-2 positive. Overall, this bioassay can facilitate breast cancer diagnosis and prognosis in clinical scenarios and resource-limited areas.