Tunable emission colors are shown by a single‐component emitter incorporating an EuIII moiety as the origin of red light and an organic ligand comprising coumarin (blue emission) and Rhodamine 6G (green emission) fluorophores. This dye can emit three individual primary colors (blue, green, and red) as well as nearly pure white light (see picture).

An inorganic–organic silica material (SBA–P2), prepared by immobilization of the 1,8‐naphthalimide‐based receptor P2 within the channels of the mesoporous silica material SBA‐15, is characterized by transmission electron microscopy and several spectroscopic methods. SBA–P2 features a high affinity Cu2+‐specific fluorescence response in aqueous solution with a detection limit for Cu2+ of ca. 0.65 ppb (10 × 10−9 M) under optimized conditions. It can extract Cu2+ from the solution with only trace amounts remaining. Through isolating of the toxic ions within the mesopores of the silica, SBA–P2 has the potential to work as a toxicide for Cu2+ in living systems. The fluorogenical responses are reversible and do not vary over a broad (4.0 to 9.0) pH range suitable for application under physiological conditions. The fluorescence responses of Cu2+ in vitro (human breast cancer cells) and in vivo (five‐day‐old zebrafish) demonstrate the possibility of further application in biology.

A new Cu2+ compound Cu- NB, (where H2 NB is bis(2-hydroxyl-naphthalene-carboxaldehyde) benzil dihydrazone) was synthesized as a highly selective fluorescence chemosensor for the detection of Hg2+ in aqueous media through a displacement "turn-on" signaling strategy. Whereas the coordination of Cu2+ resulted in a considerable quenching of the typical luminescence of the naphthol rings in Cu-NB, the addition of Hg2+ ion led to a dramatic increase in the emission intensity of Cu-NB at about 530 nm (excitation at 430 nm). The competitive fluorescent experiments showed that alkali, alkaline earth metal ions, the group 12 metals Zn2+, Cd2+, the first-row transition-metal ions such as Mn2+, Fe2+, Co2+, and Ni2+, as well as Pb2+ could not inhibit the Hg2+-binding fluorescent enhancement. It is postulated that the existence of Cu2+ in the luminescent probe Cu-NB could turn away the interferences of other metal cations from Hg2+ detection. The optical responses of the free ligand upon addition of Cu2+ ion, and of the Hg-H2NB compound upon the addition of Cu2+ were also investigated for comparisons.