We used the natural product chamomile as a carbon source to synthesize praseodymium(Pr) and nitrogen (N) co-doped biomass carbon dots (Pr/N-BCDs) with remarkable luminescence properties by one-step hydrothermal method. Compared with single N doped BCDs (N BCDs) and Prdoped BCDs (PrBCDs), Pr/N BCDs not only showed better fluorescence properties and stability but also achieved a significant increase in quantum yield of 12%. More importantly, under certain conditions, Pr/N-BCDs and 2, 4-dinitrophenylhydrazide (2, 4-DNPH) had significant fluorescence internal filtration effect (IFE) and dynamic quenching effect, and in the concentration range of 0.50-20 μmol·L^-1, the concentration of 2, 4-DNPH had a good linear relationship with the fluorescence quenching signal, and the detection limit was as low as 2.1 nmol·L^-1.

Bovine serum albumin (BSA) and glycine (Gly) dual-ligand-modified copper nanoclusters (BSA-Gly CuNCs) with high fluorescence intensity were synthesized by a one-pot strategy. Based on the competitive fluorescence quenching and dynamic quenching effects of ornidazole (ONZ) on BSA-Gly CuNCs, a simple and sensitive detection method for ONZ was successfully developed. The experimental results demonstrate that the addition of the small molecule Gly can more effectively protect CuNCs, and thus enhance its fluorescence intensity and stability. The proposed assay allowed for the detection of ONZ in a linear range of 0.28 to 52.60 μmol·L^-1 and a detection limit of 0.069 μmol·L^-1. Compared with the single-ligand-modified CuNCs, dual-ligand-modified BSA-Gly CuNCs had higher fluorescence intensity, stability, and sensing ability and were successfully applied to evaluate ONZ in actual ONZ tablets.

以硼酸与苯甲酸(BZA)为原材料，通过一步热解法合成了B掺杂的长余辉室温磷光碳量子点(B-CQDs-BZA)。采用透射电子显微镜(TEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、紫外可见(UV-Vis)吸收光谱与荧光/磷光发射光谱对B-CQDs- BZA的形貌、结构及发光性能进行表征。结果显示，合成的B-CQDs-BZA主要是由无定形碳构成的尺寸介于2.0~4.5 nm之间的零维碳量子点。B-CQDs-BZA经254与302 nm的紫外光照射后，可呈现出长达20 s的蓝色室温磷光，经测试其磷光寿命长达2.09 s。该方法简单、快速且具有普遍适用性，使用多种原材料均可合成长余辉室温磷光CQDs。基于B-CQDs-BZA卓越的室温磷光发光寿命，我们将B-CQDs-BZA成功应用于时间分辨防伪技术。另外，根据水分子对B-CQDs-BZA的猝灭效应，将其制作成湿度试纸，用来检测环境空气的湿度。

Herein, copper nanoclusters (Cu NCs) were synthesized in aqueous solution through a chemical reduction method using polyethyleneimine as reducing agent and protective ligand, with Cu(NO₃)₂ as copper source. Subsequently, composite fluorescent nanoparticles, chitosan-functionalized silica nanoparticles (CSNPs)-coated Cu NCs (Cu NCs/CSNPs), were synthesized via a reverse microemulsion method. Compared with Cu NCs, the composite Cu NCs/CSNPs exhibited an increased quantum yield and enhanced fluorescence sensing performance. Based on the composite Cu NCs/CSNPs, a fluorescence method for the detection of cefixime fluorescence quenching was established. The technique was simple, sensitive, and selective for detecting cefixime. The fluorescence quenching efficiency of Cu NCs/CSNPs was linearly related to the concentration of cefixime in the range of 3.98-38.5 μmol·L^-1 (1.81-17.46 mg·L^-1), with a limit of detection of 0.045 5 μmol·L^-1 (20.6 μg·L^-1).