Fluorescent detection of glutamate with a dicopper(II) polyamine cage

A dicopper(II) octamine cage includes selectively the l-glutamate ion in water at pH 7, establishing Cu2+/–COO− coordinative interactions. In particular, l-glutamate is able to displace the quenched rhodamine indicator from the cage, whose fluorescence is then fully restored. Other typical neurotransmitters (glycine, GABA) and some related amino acids are discriminated.