One-Pot Hydrothermal Synthesis of N-Doped Carbon Quantum Dots Using the Shrimp Powder for Highly Sensitive and Rapid Detection of Fe<sup>3+</sup>

A cost-effective and straightforward hydrothermal approach was utilized to fabricate fluorescent nitrogen-modified carbon quantum dots (N-CQDs) from shrimp powder. The N-CQDs produced possessed a mean diameter of 5 nm and demonstrated intense emission at 420 nm when optimally excited at 350 nm. Additionally, N-CQDs displayed robust blue luminescence when exposed to UV light (λ= 365 nm). Their potential as fluorescence probes for detecting Fe 3+ was investigated further. Compared to other metallic ions, N-CQDs demonstrated exceptional selectivity and sensitivity towards Fe 3+ . Moreover, N-CQDs exhibited stable and concentration-dependent fluorescent intensities with Fe 3+ concentrations spanning between 10 to 140 µM, with a minimum detectable concentration of 1.42 μM.