Highly Fluorescent <i>N</i>-Doped Carbon Quantum Dots Derived from Bamboo Stems for Selective Detection of Fe<sup>3+</sup> Ions in Biological Systems
Jiamin Yan, Yuneng Lu, Shaowen Xie, Haihu Tan, Weilan Tan, Na Li, Lijian Xu, Jianxiong Xu
Abstract
The establishment of sensing platform for trace analysis of Fe 3+ in biological systems is meaningful for health monitoring. Herein, a Fe 3+ sensitive fluorescent nanoprobe was constructed based on highly fluorescent N-doped carbon quantum dots (NCQDs) derived from bamboo stems through a hydrothermal method employing ethylenediamine as the nitrogen dopant. The prepared NCQDs had a uniformly distributed size and their mean size was around 2.43 nm. Abundant functional groups (C=N, N-H, C=O, and carboxyl) anchored on NCQDs demonstrated successful doping of N in CQDs. The obtained NCQDs possessed a high fluorescence quantum yield of 20.02% and outstanding fluorescence stability over a wide pH range and at high ionic strengths. Moreover, Fe 3+ ions presented a specific fluorescent quenching effect to the as-prepared NCQDs. The calibration curve for fluorescence quenching degree corresponding to Fe 3+ concentration showed a linear response in a range of 0.01–10 µM, and detection limit was 0.486 µM, which indicated that the NCQDs had high sensitivity to Fe 3+ ions. Ascribed to these unique properties, the NCQDs were selected as luminescent probes for trace amount of Fe 3+ ions in human serum. These results demonstrated their promising use in clinical diagnostics and other biologically relevant studies.