Detection of trastuzumab (T) level in human serum using quartz crystal microbalance (QCM) piezo-immunosensors by immobilization of a HER2 mimotope-derived synthetic peptide and its potential application in breast cancer

628 Background: Varied clinico-pathological response to monoclonal antibodies like T has been reported either due to presence of antibodies, rapid clearance or low density of target receptor/antigens. This demands need for an assay to monitor serum T therapeutic levels to ensure appropriate dosage. Enzyme-linked immunosorbent assay (ELISA) is still the most widely used technique to detect T level in human serum which is expensive and time consuming. For the first time, we established a platform to detect T level by using a small (