Rapid and Label-Free Detection of Human Epididymal Protein 4 by Piezoelectric Immunosensor

In recent years, human epididymal protein 4 (HE4), which is a new tumor marker, has been discovered with high specificity in the diagnosis of ovarian cancer. Current laboratory methods for detecting HE4, such as enzyme-linked immunosorbent assay (ELISA) and chemiluminescence immunoassay (CLIA), have the disadvantages of being time-consuming and requiring labeling steps. In this study, piezoelectric immunosensors were used to measure the concentration of HE4 antigen in PBS solution which containing various concentrations of the antigen. The performance of this immunoassay such as detection range, test time and accuracy were investigated, respectively. The results revealed that the concentration range of HE4 detected was 200–8000 pmol/ml, the analysis time was no more than 30 min and the relative error was less than 5%. Therefore, the proposed rapid and label-free piezoelectric sensing method in HE4 detection has the great potential in tumor markers detection from clinical serum for early ovarian cancer.