Method for Electrochemical Detection of Brain Derived Neurotrophic Factor (BDNF) in Plasma

Currently, a blood test for the diagnosis of endometriosis, a common estrogen-dependent gynecological disease, does not exist. Recent studies suggest that circulating concentrations of brain-derived neurotrophic factor (BDNF) have potential for the diagnosis of endometriosis. However, at present, BDNF can only be measured by ELISA, which requires a clinic visit, a routine blood sample, and laboratory testing. Therefore, we developed a point-of-care device (EndoChip) for use with small blood volumes that can be collected through a finger prick. Specifically, the presented device is a polymer-based chip with a nanoporous, wrinkled gold film acting as the electrode/sensing layer, allowing for the electrochemical detection of BDNF in plasma. Increasing concentrations of BDNF (0.1-2.0 ng/mL) induced significant differences in redox current. The biosensor produces a signal readout in a matter of seconds, and is ideal for realizing multiplexing. Blood samples were collected from women (n = 20) with chronic pelvic pain undergoing a diagnostic laparoscopy. Plasma BDNF concentrations measured by commercial ELISA were positively correlated (r(2) = 0.8033; p < 0.001) with results from the EndoChip. Our results demonstrate a quick and reliable method for point-of-care quantification of circulating concentrations of BDNF and a promising diagnostic tool for endometriosis.