Two-photon fluorescence imaging of DNA in living plant turbid tissue with carbazole dicationic salt

This is the authors' abstract. We don't add key points for this paper.

Three carbazole dicationic salts, namely 3,6-bis(1-methyl-4-vinylpyridinium) carbazole diiodide (BMVC), 9-ethyl-3,6-bis(1-methyl-4-vinylpyridinium) carbazole diiodide (9E-BMVC) and 9-ethyl-3,6-bis(1-hydroxyethyl-4-vinylpyridinium)carbazole diiodide (9E-BHVC), were synthesized successfully. Their photophysical properties were evaluated by absorption, one- and two-photon fluorescence spectra, and their higher fluorescence intensity and larger two-photon excited fluorescence action cross-sections (Φ×δ) in the presence of DNA than those in the absence of DNA give them good DNA two-photon light-switch properties. Furthermore, their ability to image nuclei in living plant cells and turbid tissues by using two-photon excited fluorescence was carefully studied, and the experimental results indicate that these dicationic salts can exclusively label nuclei in intact living plant cells and tissues. In particular, 9E-BHVC exhibits optimized DNA labeling performance. Very importantly, compared to DAPI, 9E-BHVC can be used to carry out deeper observation using the same incident power, or can be used to obtain usable fluorescent images by using a lower incident power.