Extended Data Fig. 2: Fluorescence spectra of cis-WOOH, cis-WOH, trans-WOOH and trans-WOH.

a, Excitation and emission spectra of 50 µM cis-WOOH and cis-WOH. b, Excitation and emission spectra of 50 µM trans-WOOH and trans-WOH. Spectra were determined using a Duetta fluorescence and absorbance spectrophotometer (Horiba Scientific). cis-WOOH and cis-WOH were analyzed in milliQ water whereas trans-WOOH and trans-WOH were analyzed in 50:50 (vol:vol) milliQ water/DMSO. All readings were taken at 20 oC.