Preparation of N-Doped Carbonized Polymer Dots with Narrow FWHM Based on Single Source with Self-Alkaline Induced Hydrolysis for Fluorescence Probe.

Carbon dots have attracted considerable attention in the field of ion sensing due to their excellent optical properties and biocompatibility. Currently, arginine-based carbon dots are predominantly synthesized via hydrothermal methods, which suffer from long synthesis times and the use of a single solvent system. In this study, L-arginine was employed as the sole carbon source, utilizing its intrinsic alkalinity to adjust the solution pH. Nitrogen-doped carbon dots were synthesized in one step in an ethanol system using a microwave reactor at 210 °C. The as-prepared carbon dots exhibit an emission peak at 350 nm under 290 nm excitation, with a fluorescence quantum yield of 11.31% and a full width at half maximum (FWHM) of only 54 nm, which is significantly narrower than that of carbon dots synthesized by conventional microwave methods. A fluorescence sensor for Fe³⁺ constructed based on these carbon dots demonstrates good selectivity and a wide linear response range (0.5-5180µmol·L- 1), providing a simple and efficient synthetic strategy and material foundation for the development of high-performance fluorescence sensors.