Hydrophobic Carbon Nanodots with Rapid Cell Penetrability and Tunable Photoluminescence Behavior for in Vitro and in Vivo Imaging

Abstract

Tunable fluorescent emission and applications in both in vitro and in vivo imaging of hydrophobic carbon nanodots (CNDs) with rapid penetration capability are reported. The hydrophobic CNDs are prepared via hydrothermal treatment of ionic liquid 1-ethyl-3-methylimidazolium bromide and exhibit excitation-dependent photoluminescence behavior along with a red-shift in the excitation/emission maxima with concentration. The quantum yields of the as-prepared CNDs are in the range of 2.5-4.8% at an excitation wavelength of 300-600 nm. The rapid penetration behavior (within 1 min) of CNDs into the cell membrane significantly reduces the sample treatment time and avoids potential fluorescence quenching induced by the interaction between CNDs and samples. A co-location study reveals that the hydrophobic CNDs are distributed mainly in the lysosome. The potentials of the hydrophobic CNDs as fluorescent probe in in vitro and in vivo imaging are well demonstrated by the labeling of HeLa cells, MCF-7 cells, A549 cells, and Kunming mice.

Magnetofluorescent Carbon Quantum Dot Decorated Multiwalled Carbon Nanotubes for Dual-Modal Targeted Imaging in Chemo-Photothermal Synergistic Therapy

“…GdN@CQDs displayed extra characteristic peaks consistent with Gd 3d (1189.1 eV), and Gd 4d (142.6 eV), affirming the oxidation state of Gd 3+ in GdN@CQDs (Figure D). , The N 1s peak at 399.5 eV was attributed to N in an NH 2 state and aromatic N, but, the N 1s peak of GdN@CQDs at 398.8 eV was attributed to N at the surface and NH 2 (Figure S2). The XRD patterns of GdN@CQDs did not show well-demarcated diffraction peaks, possibly due to an amorphous carbon structure (Figure S3). Different from the XRD pattern of GdCl 3 , no diffraction peaks were detected in responding to free Gd 3+ , reveling that Gd 3+ was tightly chelated with the NCQDs and the coordination between Gd 3+ and N@CQDs caused the preparation of GdN@CQDs .…”

Facile and large-scale synthesis of green-emitting carbon nanodots from aspartame and the applications for ferric ions sensing and cell imaging

“…The O 1s spectrum (Fig. 2d) was deconvoluted into three components located at 531.1, 531.9 and 533.3 eV, which are associated with C@O [42], CAOH [38] and CAOAC groups [43], respectively. Consistent with the FT-IR results, XPS results confirm the existence of the polycyclic heterocycles and abundant hydrophilic groups on surface of N-CDs (e.g., hydroxyl, amino and carboxylic groups).…”

Amphiphilic-like carbon dots as antitumoral drug vehicles and phototherapeutical agents

“…Design of the synthesis of LCDs hCDs are promising nanoparticles that are synthesized by the use of water-insoluble binary mixtures of a carbon source and a capping agent [9][10][11][12][13][14] or by specific post-synthesis functionalization of hydrophilic CDs. 15,17 We envisioned a twostep synthesis consisting of a first step of thermolysis of CA, to yield CDs functionalized with acid anhydride groups (AA-CDs), 37 and a second step of reaction with alkyl amines to yield the grafting of the hydrophobic alkyl moiety via an amide linkage, with the concomitant formation of a carboxylic group.…”

“…Reports on CDs that are soluble in non-aqueous solutions, termed hydrophobic CDs (hCDs), are still scarce. In general, the synthesis involves either the use of a water-insoluble binary mixture of a carbon source and a capping agent [9][10][11][12][13][14] or the specific post-synthesis functionalization of hydrophilic CDs 15,16 , although polysaccharides 17 and microwave assisted synthesis 18 have also been reported. hCDs bearing an aliphatic chain are an emerging subgroup that has focused the interest of researchers.…”

“…20 The compatibility of hCDs with biological membranes facilitates their traversing. 14,25,26 This feature is attractive for biomedical applications, in particular in cancer, where drug resistance and low specificity urge the development of new drugs whose fate may be compromised by solubility, stability and clearance rate, as illustrated by the paradigmatic case of campothecin. 27 Additionally, the side effects of anticancer agents are a challenge that demands new therapeutic approaches, among them the use of nanoparticles for photothermal therapy.…”