An Aggregation-Induced Emission Nanosensor for Real-Time Chemiluminescent Sensing of Light-Independent Intracellular Singlet Oxygen.

Abstract

Characterizing the transient ultratrace light-independent intracellular singlet oxygen (1O2), which plays a vital role in multiple biological processes in living organisms, brings about tremendous help for understanding the nature of 1O2-mediated or related bioevents. Nevertheless, an approach to detect the light-independent intracellular 1O2 is hard to find. Herein, we developed a chemiluminescent nanosensor by compacting a great number of TPE-N(Ph)-DBT-PH molecules in one nanostructure via autoaggregation. Taking advantage of the aggregation-induced emission property, this TPE-N(Ph)-DBT-PH nanosensor is highly fluorescent and promises a bright red-light CL and the convenience of mapping in vivo sensor distribution. Experiments demonstrate the nanosensor's unprecedented selectivity toward 1O2 against other reactive oxygen species. The 3.7 nmol L-1 limit of detection renders this nanosensor with the best-known sensitivity of 1O2 chemical sensors. Meanwhile, fluorescence confocal microscope imaging results suggest that our nanosensor simultaneously targets mitochondria and lysosomes in RAW 264.7 cells via the energy-dependent endocytosis pathway, thereby implying an attractive potential for the detection of intracellular 1O2. Such a potential is demonstrated by detecting 1O2 in RAW 264.7 cells during a lipopolysaccharide and phorbol myristate acetate stimulated respiration burst. This study represents the first approach to detect light-independent intracellular 1O2 during cell bioregulation. Thus, our nanosensor provides an effective tool for investigating the 1O2-related bioprocesses and pathological processes.