Solid-Phase Pyrolysis Synthesis of Highly Fluorescent Nitrogen/Sulfur Codoped Graphene Quantum Dots for Selective and Sensitive Diversity Detection of Cr(VI)

In this study, a simple one-step solid-phase pyrolysis synthesis procedure was employed to prepare N and S codoped highly fluorescent graphene quantum dots (N/S-GQDs). The as-synthesized quantum dot showed lambda excitation-dependent blue fluorescence (FL) emission with a relative quantum yield of about 22% and displayed good biocompatibility, high water dispersibility, and excellent stability under extreme conditions (i.e., ionic strength, pH, and temperature). The potential applicability of the as-synthesized quantum dot was tested by employing solution-and paper-based FL detection modes for Cr(VI) detection. The proposed solution-and paper-based FL sensors showed lower limit of detection (LOD) values of 0.01 and 0.4 mu M, respectively. The as-constructed paper-and solution-based FL sensors proved the feasibility of sensitive, cost-effective, and on-site detection of Cr(VI).

Automated summary

In this study, N and S codoped highly fluorescent graphene quantum dots (N/S-GQDs) were prepared using a simple one-step solid-phase pyrolysis synthesis procedure. The as-synthesized quantum dot exhibited blue fluorescence emission dependent on excitation wavelength, with a relative quantum yield of about 22%, and showed good biocompatibility, high water dispersibility, and excellent stability under extreme conditions (ionic strength, pH, and temperature). The applicability of the as-synthesized quantum dot was demonstrated through solution-and paper-based fluorescence (FL) detection modes for Cr(VI) detection, with lower limit of detection (LOD) values of 0.01 and 0.4 μM, respectively. The paper-and solution-based FL sensors constructed in this study proved the feasibility of sensitive, cost-effective, and on-site detection of Cr(VI).