Precise and rapid sensing of Fe(III) under concerned facile conditions is important in environmental monitoring. Herein, a facile and label-free ratiometric sensor is constructed for selective determination of Fe(III) ions by coupling second-order scattering (SOS) and fluorescence. We were synthesized fluorescent N, S-doped carbon dots (N/S-CDs) via facile one-step hydrothermal treatment with an intensive fluorescence and a weak SOS signal and high quantum yield (32%). The fluorescence of N/S-CDs was quenched whereas the intensity of SOS was relatively increased by Fe(III) ions due to aggregation-induced fluorescence quenching or enhancement. Based on this effect, a novel fluorescent ratiometric probe with the combined fluorescence and SOS is proposed for the sensing of Fe(III) ions, and with the detection limit of 83 nM and linear range of 0.1–10 μM and 10–40 μM, respectively.

中文翻译：

---

基于双发射 N/S 掺杂碳点的比例荧光和光散射传感器，用于高精度检测 Fe(III) 离子。

在相关便利条件下精确快速检测 Fe(III) 在环境监测中非常重要。在此，构建了一种简便且无标记的比例传感器，用于通过耦合二阶散射 (SOS) 和荧光来选择性测定 Fe(III) 离子。我们通过简便的一步水热处理合成了荧光 N、S 掺杂碳点 (N/S-CD)，具有强荧光和弱 SOS 信号以及高量子产率 (32%)。N/S-CD 的荧光被淬灭，而 SOS 的强度由于聚集诱导的荧光淬灭或增强而被 Fe(III) 离子相对增加。基于这种效应，提出了一种结合荧光和 SOS 的新型荧光比率探针，用于检测 Fe(III) 离子，检测限为 83 nM，线性范围为 0。