One-pot synthesis of nitrogen-doped carbon dots for highly sensitive determination of cobalt ions and biological imaging

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2021-05, Vol.252, p.119541, Article 119541
• Main Authors: Tian, Min, Zhang, Junqiu, Liu, Yaoming, Wang, Yingte, Zhang, Yong
• Format: Article
• Language: English
• Subjects: Biological imaging; Cobalt ions; Determination; Nitrogen-doped carbon dots
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2021.119541

A novel green-emitting nitrogen-doped carbon dots (N-CDs) had been successfully prepared using p-phenylenediamine and asparagine as precursors by one step hydrothermal-assisted method. The proposed N-CDs, which held extraordinary water dispersibility, high photostability and remarkable biocompatibility, could selectivity and specificity determine Co2+ based on the inner filter effect. Interestingly, the fluorescence of N-CDs was quenched linearly in the 0.3–65 μM Co2+ concentrations range, under the optimum conditions, displaying a fast response toward Co2+ with the detection limit of 22 nM. Furthermore, this method was applied to analyze the content of Co2+ in actual samples with satisfying results. More importantly, the N-CDs were utilized as the imaging probe of live root tip tissue of Arabidopsis thaliana, which effectively overcame the short-wavelength emission of N-CDs analysis technology defects and possessed significant theoretical research meaning in the fields of biological correlation analysis, environmental monitoring and disease diagnosis. [Display omitted] •The green emission N-CDs were synthesized using cheap and low-toxic raw materials.•The N-CDs can be used for the sensitive determination of Co2+.•The N-CDs were applied for actual samples analysis.•The N-CDs were also used for bioimaging owing to their excellent biocompatibility. In this work, a facile, economical and green method for the preparation of nitrogen-doped carbon dots (N-CDs) was established via hydrothermal synthesis using p-phenylenediamine and asparagine. The as-prepared N-CDs were characterized by Transmission electron microscopy (TEM), X-ray diffraction patterns (XRD), Raman, Fourier transform infrared spectroscopy (FT-IR) and other methods. Furthermore, the N-CDs showed high sensitivity toward cobalt (II) ion (Co2+). Interestingly, the fluorescence of N-CDs was quenched linearly in the 0.3–65 μM Co2+ concentrations range, under the optimum conditions, displaying a fast response toward Co2+ with the detection limit as low as 22 nM. Simultaneously, this method was applied in the analysis of water samples with considerable results. Finally, the N-CDs were successfully utilized as the imaging probe of live root tip tissue of Arabidopsis thaliana, demonstrating that the N-CDs possessed significant theoretical research meaning in the fields of biological correlation analysis, environmental monitoring and disease diagnosis.