Curcumin is essentially non fluorescent and unstable in water A weak broad emission can be detected at 550 nm using 420 excitation In a non polar environment such as a lipid membrane or after curcumin binds to serum albumin the fluorescence is increased and blue shifted with a 498 nm emission maximum using 420 nm excitation Biochim Biophysics Acta 1760 2006 1513 1520