Label-free biodetection using Capacitive Micromachined Ultrasonic Transducers (CMUTs) and its application for cardiovascular disease diagnostics

Abstract

In this study, Capacitive Micromachined Ultrasonic Transducers (CMUTs) were used to detect protein using two different schemes involving antibody detection and biomarker or antigen detection. For antibody detection, anti-human IgG Fab-specific was used as an antibody that specifically adsorbs on human IgG functionalized CMUT devices and anti-goat IgG was chosen as a non-specific negative control. We achieved a significant higher signal for the specific antibodies (~10-500 ng/ml) on CMUT devices in comparison to the non-specific negative control at low concentration. For antigen detection, we were interested in a cardiovascular disease biomarker and chose the tumor necrosis factor alpha (TNF-α) as the analyte. We found a linear calibration curve for TNF-α at very low concentrations and demonstrated that this label-free biodetection has a general applicability for assays including diagnostics of cardiovascular disease. © 2012 Eaimkhong S, et al.