Physics

Organic chemistry

Optics

Resolution (logic)

Brightness

Artificial intelligence

Photoexcitation

Chemistry

Rhodamine

Computer science

Quantum mechanics

Intramolecular force

Photochemistry

Excitation

Fluorescence

Journal of the American Chemical Society

Insufficient brightness of fluorophores poses a major bottleneck for the advancement of super-resolution microscopes. Despite being widely used, many rhodamine dyes exhibit sub-optimal brightness due to the formation of twisted intramolecular charge transfer (TICT) upon photoexcitation. Herein, we have developed a new class of quaternary piperazine-substituted rhodamines with outstanding quantum yields (Φ = 0.93) and superior brightness (ε × Φ = 8.1 × 104 L·mol–1·cm–1), by utilizing the electronic inductive effect to prevent TICT. We have also successfully deployed these rhodamines in the super-resolution imaging of the microtubules of fixed cells and of the cell membrane and lysosomes of live cells. Finally, we demonstrated that this strategy was generalizable to other families of fluorophores, resulting in substantially increased quantum yields.

Quaternary Piperazine-Substituted Rhodamines with Enhanced Brightness for Super-Resolution Imaging