Stable fluorescent gold nanoparticles for detection of Cu2+ with good sensitivity and selectivity

A simple and one-pot method for the synthesis of water-soluble, red-emitting, highly fluorescent gold nanoparticles has been reported using 11-mercaptoundecanoic acid (11-MUA) as the protecting group. We found that the fluorescent gold nanoparticles could selectively detect copper ions in aqueous solution, with a limit of detection of about 87 nM.