Validation of the chemiluminescent platform for smartphone measurement of H2O2 in human exhaled breath condensates. Measurements were made using 3.4 mM BPEA, 3.2 mM imidazole, and 1.9 mM CCPO in 9:1 EtOAc:CH3CN, and 75 µL aliquots of exhaled breath condensate using an iPhone 6 and the camera application VSCO (with exposure set to 3.0, ISO set to 1856, and the shutter speed set to 1/2). Images were acquired 2–3 seconds after addition of the exhaled breath condensate as the final reagent. Amplex Red measurements were made according to the manufacturer's instructions using 150 µL aliquots for calibration and exhaled breath condensate measurement. Error bars are ± S.D (n = 3).