An “On–Off–On” Fluorescence Sensing System Based on Nitrogen-Doped Carbon Quantum Dots (N-CQDs) and Ferric Ions (Fe3+) for the Determination of Captopril (CAP) in Real Samples - Shenyi Ye; Jingrui Cai; Ruyu Ding; Hang Zhu; Jiecheng Xiao; Tianhui Liu; Chengfei Zhao (Journal of Fluorescence, 2026)