One-Step Synthesis of Zr/Cl-Doped Carbon Dots as Fluorescent Probes for the Determination of Rutin

Abstract

Zr and Cl double-doped carbon dots (Zr/Cl-CDs) were prepared by a one-step hydrothermal method using citric acid, urea, and ZrCl₄ as precursors. Zr/Cl-CDs were characterized by ultra-violet-visible spectroscopy (UV-Vis), transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy (XPS). Experimental analysis revealed that the average size of Zr/Cl-CDs was 2–3 nm, while XPS analysis revealed the presence of C–Cl and Zr–O bonds. The fluorescence quantum yield of the final CDs was 17.5% at the excitation of 360 nm. In addition, Zr/Cl-CDs exhibited excellent performance in the detection of rutin with a concentration of 30–110 and 100–160 μmol/L, respectively. Linear correlation coefficients (R²) were 0.9931 and 0.9962. The underlying mechanism was that rutin had an excellent quenching effect on the emission of the Zr/Cl-CDs as the fluorescence intensity exhibited a good linear relationship between rutin concentration and fluorescence intensity. These findings provide a new strategy for synthesizing double-doped CDs for rutin detection.