Wavelength-Sequential Generation of Multi-Emissive Fluorophores for Site-Selective Fluorescence Nanoscopy
Year: 2026
Type: preprint
Abstract: Photoactivatable fluorophores are indispensable tools for super-resolution microscopy, but their performance is often hindered by the need for caging group chemistry, ultraviolet activation, interfering triplet-state photochemistry, and most importantly resulting in a single emissive scaffold. Here, we report a hydroacridine-based fluorophore that addresses the often encountered limitations by providing caging-group-free activation using visible light. A heteroatom-engineering strategy enables rapid singlet-state proton-coupled electron transfer, converting a blue-emissive precursor into two highly fluorescent acridinium states with distinct green (ΦF ≈ 0.80) and red (ΦF ≈ 0.78) emission by a two-step photoconversion using blue and green light sequentially. The process operates efficiently under physiological conditions without involving triplet biradical intermediates, enhancing compatibility with live-cell imaging. The fluorophore architecture further supports organelle-targeted imaging and photoinduced intracellular redistribution, enabling multicolour visualization from a single molecular scaffold, serving both spatial and temporal control over the photoactivation. These findings provide new strategies for heteroatom-controlled visible-light photoactivation and fluorophore design, providing a new platform for next-generation super-resolution imaging.
Source: ChemRxiv
Language: English
Subfield: Biophysics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7220361257