Aggregation-induced emission: a simple strategy to improve chemiluminescence resonance energy transfer.

The emergence of aggregation-induced emission (AIE) has opened up a new avenue for scientists. There is a great demand for the development of a new generation chemiluminescence resonance energy transfer (CRET) acceptors with AIE characteristics due to the aggregation-caused chemiluminescence (CL) quenching effect commonly observed in the conventional fluorophore CL acceptors at high concentrations. However, the systematical studies involving in AIE-amplified CL are still scarce. Herein, it is the first report that the gold nanocluster aggregates (a type of well-defined AIE molecules) are used to study their influence on the bis(2,4,6-trichlorophenyl) oxalate (TCPO)-H2O2 CL reaction. Interestingly, the AIE molecules in the diluted solution are unable to boost the CL signal of the TCPO-H2O2 system, but their aggregates display a strongly enhanced CL emission compared to their counterparts of fluorophore molecules, thanks to the unique AIE effect of gold nanoclusters. In comparison to rhodamine B with the aid of an imidazole catalyst, the detection limit of the gold nanocluster aggregate-amplified CL probe for H2O2 (S/N = 3) is low in the absence of any catalyst. Finally, the other two typical AIE molecules, Au(I)-thiolate complexes and 9,10-bis[4-(3-sulfonatopropoxyl)-styryl]anthracene (BSPSA), are investigated to verify the generality of the AIE molecule-amplified CL emissions. These results demonstrate effective access to highly fluorescent AIE molecules with practical applications in avoiding the aggregation-induced CL quenching at high concentrations, which can be expected to provide a novel and sensitive platform for the CL amplified detection.