PT  - JOURNAL ARTICLE
AU  - Aleksander M. Shakhov
AU  - Artyom A. Astafiev
AU  - Alina A. Osychenko
AU  - Maria S. Syrchina
AU  - Viktor A. Nadtochenko
TI  - Live cell bioimaging with carbon dots produced in situ by femtosecond laser from intracellular material
AID  - 10.1101/455808
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 455808
4099  - http://biorxiv.org/content/early/2019/01/09/455808.short
4100  - http://biorxiv.org/content/early/2019/01/09/455808.full
AB  - Owning to excellent optical properties and high biocompatibility carbon dots (CDs) have drawn increasing attention and have been widely applied as imaging agents for various bio-applications. Here we report a strategy for live-cell fluorescent bioimaging based on in situ synthesis of CDs within cells by tightly focused femtosecond laser pulses. Laser-produced carbon dots exhibit bright excitation-dependent fluorescence and are highly two-photon active under near infrared femtosecond excitation, thus demonstrating a potential for two-photon fluorescence imaging. The Raman spectra of fluorescent centers show strong D (1350 cm-1) and G (1590 cm-1) bands, thus suggesting that they are composed of carbon dots with sp2-hybridized core. Using Mouse GV oocytes as a model system we examine cytotoxicity and demonstrate the possibility of long-term fluorescent intracellular tracking of the laser-produced CDs. Created virtually in any point of the live cell, CD-based fluorescent μm-sized markers demonstrate high structural stability and retain bright fluorescence many hours after formation. Our results point to laser-produced fluorescent CDs as a highly-potent tool for cell cycle tracking, culture cell marking and probing intracellular movements.