Preparation of IRDye800-coated PFOB nanoemulsions. To fabricate perfluorooctylbromide (PFOB, Aldrich, St. Louis, MO)] nanoemulsions, PFOB liquids were emulsified in an aqueous solution using surfactant mixtures. A surfactant mixture comprising of 64 mol % lecithin (L-α-Phosphatidylcholine 95%, chicken egg, Avanti Polar Lipids, Alabaster, AL), 35 mol % cholesterol (Avanti Polar Lipids, Alabaster, AL) and 1 mol % 1,2-distearoyl-sn-glycero-3phosphoethanolamine-N-[amino(polyethylene glycol)-2000]

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... mmonium salt) (DSPE-PEG (2000) Amine, Avanti Polar Lipids, Alabaster, AL) were dissolved in chloroform, and the organic solvent was evaporated using a rotary evaporator and a vacuum oven (50°C) for 24 h. After dispersing the surfactant mixture into sterilized distilled water, the solution was sonicated. PFOB liquids (40% v/v), glycerin (2.0% w/v), surfactant mixture and distilled water were mixed for 30 s using a homogenizer. The mixture was processed through an emulsifier (M-110S, Microfluidics, Newton, MA) at 20000 psi for 3 min. The fabricated PFOB nanoemulsions were stored at 4°C. As a nearinfrared fluorophore, IRDye800 NHS ester was purchased from LI-COR Biosciences (Licoln, Nebraska). For conjugation, an aliquot of PFOB nanoemulsion solutions were mixed with IRDye800 NHS ester (50 μL/mg) dissolved in water. The conjugation reaction was carried out for 2 hrs at 20 °C . IRDye800-coated PFOB nanoemulsions were separated using FPLC system. Supplementary Material (ESI)