Simultaneous Fluorescence and Chemiluminescence Turned on by Aggregation-Induced Emission for Real-Time Monitoring of Endogenous Superoxide Anion in Live Cells.

Biological sensors with simultaneous turn-on signals of fluorescence (FL) and chemiluminescence (CL) triggered by one single species are supposed to integrate spatiotemporally resolved FL imaging with dynamic CL sensing into one luminescent assay. Efficiently increased accuracy can be expected based on complementary information simultaneously obtained from two independent modes, which is crucial in disease detection and diagnosis. However, very few examples can be found to date because of the key challenges in the rational design of sensing structures. Herein, aggregation-induced emission (AIE) was employed to develop a novel organic platform TPE-CLA with simultaneous turn-on FL/CL signals specifically modulated by O2•- in cells, which can be attributed to the activation of AIE resulted from the decreasing solubility after recognition. Using imidazopyrazinone (CLA) as the reactive motif and tetraphenylethene (TPE) as FL/CL enhancing skeleton, TPE-CLA is sensitive enough to image native O2•- in Raw264.7 cells and lipopolysaccharide stimulated O2•- in mice. Endogenous O2•- in HL-7702 cells induced by acetaminophen (APAP) was uninterruptedly monitored for 7200 s with CL and the results were further confirmed by FL imaging. Accordingly, TPE-CLA turns out to be a reliable candidate for real-time and continuous monitoring of endogenous O2•- in live cells. The strategy utilizing AIE to accomplish the FL/CL dual detection is expected to extend the application of AIE as reaction-activated biosensors.