Triphenylamine-equipped 1,8-naphthaolactam: a versatile scaffold for the custom design of efficient subcellular imaging agents

Fluorescence imaging has enabled much progress in biological fields, while the evolution of commercially available dyes has lagged behind their advanced applications. Herein, we launch triphenylamine-equipped 1,8-naphthaolactam (NP-TPA) as a versatile scaffold for the custom design of an efficient subcellular imaging agent (NP-TPA-Tar), given its bright and constant emissions in various states, significant Stokes shifts, and facile modifiability. The resultant four NP-TPA-Tars maintain excellent emission behavior with targeted modifications and can map the spatial distribution of lysosomes, mitochondria, endoplasmic reticulum, and plasma membrane in Hep G2 cells. Compared to its commercial counterpart, NP-TPA-Tar has a 2.8-25.2 fold increase in Stokes shift, a 1.2-1.9 fold increase in photostability, enhanced targeting capability, and comparable imaging efficiency even at low concentrations of 50 nM. This work will help to accelerate the update of current imaging agents and super-resolution and real-time imaging in biological applications.

Automated summary

By utilizing triphenylamine-equipped 1,8-naphthaolactam (NP-TPA) as a versatile scaffold, an efficient subcellular imaging agent (NP-TPA-Tar) was designed with bright and constant emissions, significant Stokes shifts, and easy modifiability. The NP-TPA-Tar can efficiently map the spatial distribution of lysosomes, mitochondria, endoplasmic reticulum, and plasma membrane in Hep G2 cells. Compared to its commercial counterpart, NP-TPA-Tar exhibits increased Stokes shift, enhanced photostability, improved targeting capability, and comparable imaging efficiency even at low concentrations (50 nM). This work will advance the development of imaging agents and improve super-resolution and real-time imaging in biological applications.