Rational synthesis of highly efficient ultra-narrow red-emitting carbon quantum dots for NIR-II two-photon bioimaging

Nanoscale. 2020 Jan 23;12(3):1589-1601. doi: 10.1039/c9nr09524a.

Abstract

Despite the growing research interest in highly bio-compatible carbon quantum dots (CQDs) for bioimaging, the synthesis of red-emitting CQDs with high photoluminescence efficiency and a sharp emission spectrum remains a formidable challenge in this field. Herein, we established a rational strategy for the synthesis of highly efficient ultra-narrow red-emitting CQDs by adopting a conjugated aromatic amine precursor (tris(4-aminophenyl)amine, TAPA) and introducing oxidative radical reagents. The resultant CQDs, T-CQDs featured red PL (615 ± 2 nm) with a high photoluminescence quantum yield (84 ± 5%) and a narrow emission linewidth (FWHM = 27 ± 1 nm), which together represented one of the highest levels in the field of CQDs so far. The T-CQDs were then further analyzed from the spectral and structural aspects, and the repeatability and universality of this strategy have also been discussed. Finally, the T-CQDs were successfully applied for both one-photon imaging and two-photon imaging with various bio-samples, both in vitro and in vivo.

MeSH terms

  • Animals
  • Carbon* / chemistry
  • Carbon* / pharmacology
  • Female
  • HeLa Cells
  • Humans
  • MCF-7 Cells
  • Mice
  • Mice, Inbred BALB C
  • Microscopy, Fluorescence, Multiphoton
  • NIH 3T3 Cells
  • Neoplasms, Experimental / diagnostic imaging*
  • Neoplasms, Experimental / metabolism
  • Quantum Dots / chemistry*
  • Spectroscopy, Near-Infrared
  • Zebrafish

Substances

  • Carbon