An Electronic Sensor for Detection of Early-Stage Biomarker/s for Ovarian Cancer

An electronic sensor composed of interdigitated electrode arrays with nano-scale gaps has been investigated as a platform for label-free detection of ovarian cancer (OC) biomarkers. These electrodes, together with bio-affinity label-free sandwich immunoassay, were utilized as signal transducers. Electrochemical impedance spectroscopy (EIS) was employed as a technique for detection of affinity type interactions at the electrode surface. An unconventional approach is described for label-free impedimetric detection using faradic EIS at a DC bias less than the formal potential of the redox probe using nanogapped IDEAs as the transducing elements. The platform was optimized for detection of HE4, a biomarker for OC that is indicated in the early and late stages of the disease, along with CA-125 and CEA as conventional biomarkers that are currently used for diagnosis and monitoring of OC patients. The capability of the sensor platform to detect OC biomarkers in singular and multiplexed detection has been demonstrated. The sensor was successfully utilized for stand-alone detection of HE4 down to 1.5 ng/mL and was able to differentiate signal from three different biomarkers present in the same sample down to 100 pg/mL in a label-free biosensor assay.