The on–off-on Fluorescence Sensor of Hollow Carbon Dots for Detecting Hg2+ and Ascorbic Acid

• Published in: Journal of fluorescence Vol. 33; no. 2; pp. 459 - 469
• Main Authors: Hao, Yunping, Li, Ronghui, Liu, Yanxu, Zhang, Xuhong, Geng, Lina, Chen, Shenna
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.03.2023; Springer Nature B.V
• Subjects: Analytical Chemistry; Ascorbic acid; Biochemistry; Biological and Medical Physics; Biomedical and Life Sciences; Biomedicine; Biophysics; Biotechnology; Carbon dots; Citric acid; Fluorescence; Fourier transforms; Infrared spectroscopy; Mercury (metal); NMR; Nuclear magnetic resonance; Photoluminescence; Pyrolysis; Quantum dots; Zeta potential; Fluorescence; Ascorbic acid; Carbon dots; Mercury ions
• ISSN: 1053-0509; 1573-4994; 1573-4994
• DOI: 10.1007/s10895-022-03057-3

Carbon dots (CDs) have excellent fluorescence properties and can be used in many research fields. In this paper, carbon dots were prepared by microwave-assisted pyrolysis of citric acid and urea, characterized by transmission electron microscope (TEM), X-ray diffractometer (XRD), 13 C-NMR spectrum, zeta potential, Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible (UV–vis) absorption and fluorescence spectra, and detected the Hg 2+ and ascorbic acid (AA) sequentially. It showed that carbon dots were hollow, spherical particles and less than 10 nm, photoluminescence quantum yield of carbon dots was about 15%. The CDs were selective and sensitive to Hg 2+ and AA based on the “on–off-on” fluorescence behavior. The detection limits of CDs for Hg 2+ and AA were 0.138 μM and 0.212 μM, respectively. Fluorescence response mechanism of CDs was also discussed.