Green One-step Pyrolytic Synthesis of Folic Acid-Derived Carbon Dots for Sensitive Turn-on Fluorescence Detection of Cysteine

This study introduces a straightforward one-step pyrolytic method for synthesizing carbon dots derived from folic acid (FACDs). This green and cost-effective approach simplifies the production of fluorescent carbon nanomaterials, which exhibit strong and stable fluorescence properties. These properties make FACDs particularly suitable for the sensitive and selective detection of cysteine (Cys) through a "turn-on" fluorescence mechanism. The FACDs demonstrate a low detection limit of 1.7 × 10⁻⁷ M and a broad linear range from 5.0 × 10⁻⁷ to 8.0 × 10⁻ 5M, effectively restoring quenched fluorescence in the presence of Cys. These results underscore the potential of FACDs as reliable, high-performance sensors for various biological and environmental applications, paving the way for the development of versatile and efficient fluorescence-based detection platforms.