Quenching Properties of a Self-Referenced Fluorescence Oxygen Nanosensor under a Wide-Field Intrinsic Optical Signal Imaging System

Wide-field intrinsic optical signal (IOS) imaging is an excellent method to map in vivo neurological metabolic changes during brain activity. It has a spatial resolution of 50-100 mum and a wide imaging field of several cm² that cannot be achieved by regular microscopic imaging. A nano-encapsulated fluorescence dye sensor that is specifically sensitive to oxygen level was fabricated by using electrostatic layer-by-layer (LbL) self-assembly technique. Fluorescence images of the nanosensor solution were collected by a wide-field IOS imaging system under different oxygen concentrations. Mathematical models for nanosensor fluorescence were developed based on the imaging results. Correlations between the nanosensor fluorescence and oxygen concentration models indicate an inverse quenching relationship between the nanosensor fluorescence and oxygen concentration