Structurally Ordered Catalyst-Amplified Chemiluminescence Signals.

Highly ordered structure of catalysts could spring up unique properties in catalytic activities. There is apparently no good reason to disregard the structurally ordered catalyst-amplified chemiluminescence (CL) signals. Herein, we have fabricated the structurally ordered ionic liquid-layered double hydroxide (LDH) assembly through the hydrogen bonding interactions between abundant hydroxyl groups on the surfaces of LDHs and the amino groups in 1-(3-aminopropyl)-3-methyl-imidazolium tetrafluoroborate ([apmim]BF4). Interestingly, we found that the CL signals of luminol-H2O2 system in the presence of structurally ordered [apmim]BF4 ionic liquid-LDH assembly were extraordinarily enhanced, in comparison with those in the presence of the disordered 1-aminoethyl-3-methyl imidazolium tetrafluoroborate ([aemim]BF4) ionic liquid-LDH assembly. The improved CL performances of the structurally ordered [apmim]BF4 ionic liquid-LDH assembly were attributed to the increasing amounts of superoxide anion radicals (O2•-) and hydroxide radicals (•OH) by accelerating of the mass transport from the solution to the surface of ionic liquid-LDH assembly. In addition, such a highly orderly arrangement could increase the emission of the luminol oxidation products by facilitating the electron transfer. Our findings open up new possibilities in the structurally ordered catalyst-enhanced CL emissions, which can be expected to provide a novel and sensitive platform for the CL amplified detection.