Dual-Emissive Probe for Reversible Visualization of ΔΨ_m Revealing Voltage Heterogeneity in a Single Mitochondrion

Mitochondrial membrane potential (ΔΨ_m) is a fundamentally important parameter in eukaryotic cells playing central roles in various vital biological processes. Precise visualization of ΔΨ_m depends on the robust ratiometric fluorescent probes. In this work, a new dual-emissive fluorescent probe has been fabricated for ratiometric visualization of ΔΨ_m. The unique probe can form near-infrared emissive aggregates (∼670 nm) in mitochondria with high ΔΨ_m, which turned to green-emitting monomers (530 nm) with loss of ΔΨ_m. The reversible changes of ΔΨ_m can be clearly observed, and the ultralarge emission shift (∼140 nm) is greatly favorable for the clear observation of voltage distribution under a super-resolution microscope. With the robust probe, the heterogenous voltage distribution in a single mitochondrion has been revealed for the first time, which can facilitate the in-depth understanding of fine structures in mitochondria. The cell damages induced by various reagents were successfully visualized using the innovative probe, demonstrating its pronounced potential for biological research.