One-step synthesis of amino-functionalized fluorescent carbon nanoparticles by hydrothermal carbonization of chitosan

Abstract

Highly amino-functionalized fluorescent carbon nanoparticles (CNPs) were fabricated by hydrothermal carbonization of chitosan at a mild temperature. They were applied to bioimaging of human lung adenocarcinoma A549 cells, showing low cytotoxicity and excellent biocompatibility.

Spherical nanocomposite particles prepared from mixed cellulose–chitosan solutions

“…The pure chitosan raw material shows diffraction peaks at 11.9°, 19.7°a nd 29.1°that can be assigned to (020), (110) and (130), respectively (Zhang et al 2005). The diffraction peaks at 11.9°(020) and 19.7°(110) represent the amorphous and the crystalline regions of chitosan (Yang et al 2012). The regenerated chitosan, showing a strong peak at 10.6°and a minor peak at 20.7°, has a diffraction profile, which is rather different than the raw material.…”

“…The regenerated chitosan, showing a strong peak at 10.6°and a minor peak at 20.7°, has a diffraction profile, which is rather different than the raw material. This implies a dominant amorphous feature of the regenerated chitosan (Yang et al 2012). If the compatibility between cellulose and chitosan would have been poor in the nanocomposite materials, their diffraction peaks would have been found at the same positions as in the individual, regenerated raw materials.…”

Development of multicolor carbon nanoparticles for cell imaging

“…The bathochromic emission of the CNPs has been extensively reported previously. [14,15,20,28] The emission intensity shows the highest valve of 439 nm and 405 nm for cellulose-CNPs (FWHM, 90 nm) and cyclodextrinCNPs (FWHM, 135 nm), respectively, under the excitation at 360 nm. It is reasonable to assume that the different carbon resources lead to the different excitation energy traps and the different fluorescence properties.…”

“…Preparation of fluorescent CNPs from bioprecursors may provide a new approach for bottom-up CNPs fabrications. Although carbon nanoparticles derived from [20,32] to the best of our knowledge, the direct synthesis of fluorescent CNPs from linear polysaccharides and cyclic oligosaccharides and their fluorescent properties remains less studied.…”

“…Because of these features, various methods for fluorescent CNP synthesis have been reported by using carbon-based materials as carbon resources. [14,19,20] For example, top-down methods include laser ablation of carbon powder [14], electrochemical oxidation [21] and arc discharge [22]; bottom-up methods consist of microwave synthesis, [23,24] combustion soots of candles, [25,26] thermal oxidation of carbon precursor by employing silica or zeolites as carriers [27,28] commercial activated carbon [29], lampblack [30] and watermelon peel as carbon resources [31]. All these methods suffer to some degree from drawbacks like tedious processes, harsh synthetic conditions or expensive starting materials.…”