One step synthesis of C-dots by microwave mediated caramelization of poly(ethylene glycol)

Abstract

A rapid, simple and one step microwave mediated method for synthesizing C-dots using poly(ethylene glycol) (PEG) as a precursor and passivating agent is reported. The C-dots possessed low cytotoxicity, were amenable to separation by electrophoresis, photostable and entered cancer cells, making them suitable candidates for bioimaging and biolabelling.

From highly graphitic to amorphous carbon dots: A critical review

“…48 HRTEM imaging of the aC-dots does not reveal any discernible lattice fringes, and the XRD pattern shows a broad peak at 4.1 Å, consistent with highly disordered carbon.…”

“…49 Similarly, water dispersible C-dots were prepared by controlled pyrolysis of dopamine, 54 lauryl gallate, 55 polyethylenimine, 56 or a mixture of ethanolamine and citric acid. 57 , 58 In a remarkably time-effi cient modifi cation of the method, microwave-assisted thermal treatment of an aqueous solution containing PEG 48 or a mixture of PEG and a saccharide 59 leads rapidly to selfpassivated colloidal aC-dots. Ultrasmall aC-dots with quantum yield up to 47% have been derived by 1 min pyrolysis of anhydrous citric acid in N -( β -aminoethyl)-γ -aminopropyl methyldimethoxy silane.…”

Enhanced photoluminescence and characterization of multicolor carbon dots using plant soot as a carbon source

“…However, the large scale preparation and surface passivation of C-dots are still expected to provide highly fluorescent C-dots by using economical and facile approaches. Up to now, various carbon sources have been used to prepare C-dots such as laser ablation of graphite [19,20], electrochemical treatment of graphite [21], commercial activated carbon by bottom-up method [9], heating carbohydrate, watermelon peels or PEG with microwave pyrolysis [22][23][24]. The prepared C-dots are highly water-soluble, nano-sized and multi-colourful.…”

Graphene quantum dots: In the crossroad of graphene, quantum dots and carbogenic nanoparticles

“…7f shows peaks at 284.3, 285.7 and 288.0 eV, corresponding to C=C-C, C-O and C=O groups, respectively. Despite their pronounced structural differences, C-dots [32] and GQDs [14] share common PL patterns and, as the excitation wavelength increases, the emission peak is displaced to longer wavelengths and a less intense signal is recorded (Fig. 8).…”