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

By Yushan Liu, Pengchao Wu, Chunhui Ma, Xueyun Wu, Mingcong Xu, Sha Luo, Zhou Xu, Shouxin Liu. Sensors and Actuators B: Chemical, 2019

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Abstract 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.

Subfields: Electrical and Electronic Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/298e7ac70bfeed7714215fa80b56af0572543a91