One-Pot Green Synthesis of High Quantum Yield Oxygen-Doped, Nitrogen-Rich, Photoluminescent Polymer Carbon Nanoribbons as an Effective Fluorescent Sensing Platform for Sensitive and Selective Detection of Silver(I) and Mercury(II) Ions

This work reports on a facile, economical, and green preparative strategy toward water-soluble, fluorescent oxygen-doped, nitrogen-rich, photoluminescent polymer carbon nanoribbons (ONPCRs) with a quantum yield of approximately 25.61% by the hydrothermal process using uric acid as a carbon nitrogen source for the first time. The as-prepared fluorescent ONPCRs showed paddy leaf-like structure with 80-160 nm length and highly efficient fluorescent quenching ability in the presence of mercury(II) (Hg2+) or silver (Ag+) ions due to the formed nonfluorescent metal complexes via robust Hg2+-O or Ag+-N interaction with the O and N of fluorescent ONPCRs, which allowed the analysis of Hg2+ and Ag+ ions in a very simple method. By employing this sensor, excellent linear relationships existed between the quenching degree of the ONPCRs and the concentrations of Hg2+ and Ag+ ions in the range of 2.0 nM to 60 mu M and 5.0 nM to 80 mu M, respectively. By using ethylenediaminetetraacetate and ammonia as the masking agent of He and Ag+ ions, respectively, Hg2+ or Ag+ ions were exclusively detected in coexistence with Ag+ or Hg2+ ions with high sensitivity, and the detection limits as low as 0.68 and 1.73 nM (3 sigma) were achieved, respectively, which also provided a reusable detection method for Hg2+ and Ag+ ions. Therefore, the easily synthesized fluorescent ONPCRs may have great potential applications in the detection of Hg2+ and Ag+ ions for biological assay and environmental protection.