Rapid and sensitive detection of brain-derived neurotrophic factor with a plasmonic chip

Plasmonic chips, which are grating replicas coated with thin metal layers and overlayers such as ZnO, were applied in immunosensors to improve their detection sensitivity. Fluorescence from labeled antibodies bound to plasmonic chips can be enhanced on the basis of a grating-coupled surface plasmon resonance (GC-SPR) field. In this study, as one of the representative candidate protein markers for brain disorders, the brainderived neurotrophic factor (BDNF) was quantitatively measured by sandwich assay on a plasmonic chip and detected on our plasmonic chip in the concentration of 5-7 ng/mL within 40 min. Furthermore, BDNF was detected in the blood sera from three types of mice: wild-type mice and two types of mutant mice. This technique is promising as a new clinical diagnosis tool for brain disorders based on scientific evidence such as blood test results.