Aliquots (1.0 mL) were taken from a room temperature stock solution (1.0 mM, 20 mL) of ICB in water at different time points (sample exposed to lab lights only during preparation and when aliquots were removed). At each time point, the 1.0 mL aliquot was lyophilized and the solid residue was dissolved in 0.60 mL of methanol-d4 to permit 1 H NMR (500 MHz) analysis. To measure the photostability, two separate cuvettes, each containing 1 µM of ICB or ICG in PBS buffer, pH 7.4, were irradiated at a set 3cm distance by using a 150 W Xenon lamp (Oreal Corporation, USA) equipped with a 620 nm long-pass filter (Edmunds Optics Inc., USA). ICB thermal stability was assessed by irradiating a 5 µM dye in PBS buffer, pH 7.4 with a 640 nm continuous laser (Coherent OBIS 640, Edmunds Optics, USA) for 10 minutes under a power intensity of 1 mW/cm 2 . Temperature was recorded using an infrared camera (Infrared Cameras Inc, 7320). Dye fatigue was recorded by conducting five, 10-minute heating/cooling cycles. The experiment was repeated in triplicate and averaged thermal cycles were reported.