Fluorescence modulation of 1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione by silver nanoparticles and its possible analytical application.

The effects of silver nanoparticles on the photophysical properties of 1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione, popularly known as curcumin, have been investigated using optical absorption and fluorescence techniques. Although absorption spectroscopy suggests a ground-state complex formation, fluorescence quenching data confirms a simultaneous static and dynamic quenching, inferring ground as well as excited-state complex formation. The recovery of fluorescence quenching of the curcumin-silver nanoparticle complex in the presence of ascorbic acid or uric acid emphasizes a strong interaction between the silver nanoparticles and ascorbic acid/uric acid, suggesting that fluorescence recovery after the quenching of curcumin-silver nanoparticle complexes has potential for ascorbic acid or uric acid assay development.