Facilely synthesised sulphur-doped carbon dots for highly selective determination of picric acid and for biological imaging

ABSTRACT

Here, yellow fluorescent sulphur-doped carbon dots (S-CDs) with high quantum yield (QY) of ~27.9% were synthesised from m-cresol purple by a fast and low-cost one-step hydrothermal method without other reagents. The surface morphology, functional groups and optical properties of S-CDs were characterised by high-resolution transmission electron microscope (HRTEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectrum and ultraviolet visible (UV-vis) absorption. The fluorescence intensity of S-CDs can be specifically and stably quenched by picric acid (PA) through inner filtration effect (IFE). The linearity between fluorescent intensity and PA concentration was used for developing a fluorescent probe with detecting range of 0–259.0 μM and a detection limit as low as 14.6 nM. We developed the method by applying S-CDs to determine PA in lake water with recoveries in the range of 93.0–103.7%, which verified the feasibility of this probe in practical analysis. In addition, due to the low toxicity and good biocompatibility, S-CDs can be applied to biological imaging.

KEYWORDS:

• Sulphur-doped carbon dots
• picric acid
• biological imaging
• fluorescence determination

Acknowledgments

The authors gratefully acknowledge the support for this work from the Shanxi Natural Science Foundation (201801D121074).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed here.