A high sensitive in vivo biosensing detection for odors by multiunit in rat olfactory bulb

This study presents an in vivo biosensing system for odorant detection. Taking advantage of mammal's extraordinarily sensitive olfactory systems, we extract the odorant information from conscious rats’ olfactory bulb (OB) using microelectrode array. By chronically implanting the microelectrode into OB, high-quality mitral/tufted (M/T) cell activity evoked by odorants could be obtained for at least three weeks. The responses of multiple M/T cells broadly represent information about the presented odorants. Six odorants (carvone, citral, isobutyl alcohol, diacetyl, anisole and isoamyl acetate) used in this study could be discriminated by analyzing the neuronal activity. What is more, we found the concentration detection limit of system is below 10−15 mol/L for carvone. These results demonstrate that in vivo biosensing system has characteristic of high sensitivity, continuous recording, specificity, which presents a promising platform for specific trace odorant detection in many fields.