Hydrothermal synthesis of nitrogen and boron co-doped carbon quantum dots for application in acetone and dopamine sensors and multicolor cellular imaging

• Published in: Sensors and actuators. B, Chemical Vol. 281; pp. 34 - 43
• Main Authors: Liu, Yushan, Li, Wei, Wu, Peng, Ma, Chunhui, Wu, Xueyun, Xu, Mingcong, Luo, Sha, Xu, Zhou, Liu, Shouxin
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15-02-2019; Elsevier Science Ltd
• Subjects: Acetone; Acetone sensor; Borax; Boron; Carbon; Carbon quantum dot; Citric acid; Crystal structure; Dopamine; Dopamine detection; Emission; Excitation; Fluorescence; Functional groups; Heteroatom doping; Hydrothermal carbonization; Hydrothermal crystal growth; Hydrothermal reactions; Hydrothermal treatment; Infrared spectra; Morphology; Multicolor cellular imaging; Nitrogen; Optical properties; Photoelectrons; Photoluminescence; Polyvinyl alcohol; Quantum dots; Quenching; Ultraviolet spectra; Wavelengths; LOD; PBS; AC; CQDs; DMSO; NB-CQDs; MTT; DMEM; Multicolor cellular imaging; HIV; Acetone sensor; Hydrothermal carbonization; FBS; Carbon quantum dot; Heteroatom doping; Dopamine detection; PVA; PL; DMF; DA; CA
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2018.10.075

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•Nitrogen and boron co-doped carbon quantum dots (NB-CQDs) were prepared by hydrothermal treatment of citric acid, borax and p-phenylenediamine.•The NB-CQDs showed regular photoluminescence (PL) under different excitation wavelengths, and had pH- and solvent polarity-dependent PL.•The NB-CQDs displayed great PL detection ability for acetone and dopamine, and the detection limits were 0.54 μM and 11 nM, respectively.•The NB-CQDs and poly(vinyl alcohol) composite film demonstrated good PL response to acetone vapor.•The NB-CQDs were used for multicolor cellular imaging.
Nitrogen and boron co-doped carbon quantum dots (NB-CQDs) were prepared via one-pot hydrothermal treatment of citric acid, borax, and p-phenylenediamine.
The synthesized NB-CQDs were characterized by transmission electron microscopy, Fourier-transform infrared spectra, X-ray photoelectron spectra, dynamic light scattering, ultraviolet-visible absorption and fluorescence spectra to characterize their surface morphology, crystal structure, functional groups and elemental composition, and optical properties. It was found that N and B species were efficiently doped into the carbon framework of the dots, the N- and B-Containing groups formed on the surface of NB-CQDs during the hydrothermal reaction. The element doping and surface functionalization of NB-CQDs efficiently modulated their physicochemical properties. The NB-CQDs were nearly mono-disperse with an average particle diameter of 3.53 nm, and the excitation/emission wavelengths were 360/490 nm, respectively. The NB-CQDs showed regular photoluminescence (PL) emission under different excitation wavelengths, and possessed pH-dependent and solvent polarity-dependent PL properties. In addition, the NB-CQDs and a NB-CQD/poly(vinyl alcohol) composite film showed good PL responses to acetone solution and vapor. A PL sensor for the determination of acetone solution with a limit of detection (LOD) of 0.54 μM (R2 = 0.9956) was then designed. The NB-CQDs were also used for the determination of dopamine. The PL intensity of the NB-CQDs was inversely proportional to the concentration of dopamine in the range of 0.1–70 μM (R2 = 0.9958). The LOD of dopamine was 11 nM, and PL quenching occurred via a static quenching mechanism. Additionally, these NB-CQDs can be used for multicolor cellular imaging and showed good uptake by Hepg2 cells.