Perylenetetracarboxylic anhydride as a precursor of fluorescent carbon nanoonion rings

Abstract

Royal Society of ChemistryGarcía Baldoví, H.; Víctor, VM.; Herance Camacho, JR.; Alvaro Rodríguez, MM.; García Gómez, H. (2015). Perylenetetracarboxylic anhydride as a precursor of fluorescent carbon nanoonion rings. Nanoscale. 7(29)

Toxicological properties of two fluorescent carbon quantum dots with onion ring morphology and their usefulness as bioimaging agents

“…The height of these C-NORs was determined by AFM images that show that C-NORs are at objects with a size of 2.5 nm. 31 No differences in the morphology and dimensions between C-NOR and C-NOR(Eu) could be observed and ICP-OES determined the total absence of Eu in the C-NOR(Eu) sample. However, FT-IR spectroscopy does show that the carboxylic functional groups of C-NOR(Eu) have undergone a higher level of esterication of PTA carboxylic anhydride groups when Eu 3+ is present in the thermolysis as compared to C-NOR, in accordance of the role of Eu 3+ as esterication catalyst.…”

“…Regarding to photoluminescence properties, it was found that C-NOR and C-NOR(Eu) have high uorescence emission intensity that depends on the excitation wavelength. 31 The presence of Eu 3+ in the thermolysis favors the formation of C-NOR and also increases somewhat the emission intensity band of C-NORs despite the fact that this rare earth metal ion was absent in the resulting nanoparticle. C-NOR and C-NOR(Eu) are highly emissive nanoparticles with an estimated photoluminescence quantum yield about 0.47 and 0.49, respectively.…”

“…Thermolysis in PEG has been reported as a convenient procedure for the formation of CQDs. 31,34 In the present case, PTA (see molecular structure in Scheme 1) has been used as precursor and the thermolysis in low molecular-weight PEG was carried out at 400 C in absence or presence of Eu(OAc) 3 $3H 2 O Eu 3+ , which was added to the reaction mixture as Lewis acid in order to promote the condensation of PTA with PEG in the thermal treatment. The resulting mixtures were puried by column chromatography in silica gel, collecting the fraction corresponding to the uorescent nanoparticles.…”

“…The synthesis was performed following the methodology described by our group. 31 Briey, 100 mg of PTA were suspended in 8 mL of PEG 400 in the absence (for C-NOR) or presence of 100 mg Eu(OAc) 3 $3H 2 O (for C-NOR(Eu)). The mixture was vigorously stirred at room temperature for 1 h. Then, the homogeneous mixture was placed in an oven preheated at 400 C. Subsequently, the oven was cooled down from 400 C to room temperature at a rate of À20 C h À1 .…”

“…[28][29][30] In this context, our research group has developed a new class of uorescent CQDs obtained by thermal treatment of perylenetetracarboxilic anhydride (PTA) in polyethylene glycol (PEG), in the absence or presence of Eu 3+ as Lewis acid to promote condensation of PTA with PEG. 31 Thereby, a type of CQDs with a dened and uniform morphology of onion rings was obtained, nanoonions rings (C-NORs), which exhibit a remarkable uniformity in morphology and average particle size about 40 nm, with high emission efficiency, having promising applicability in biomedicine. The use of an aromatic organic compound, such as PTA, as precursor of CQDs, offers advantages with respect to common precursors used to obtain luminescent CQDs in the thermolysis process.…”