检测环境水体中银离子含量的新型碳基光学传感器

以木质素磺酸钙为原料,通过常温下分子自组装和超声波辅助法制备木质素基碳量子点(CQDs),探究木质素磺酸钙和NaBH_(4)对CQDs荧光性能的影响并优化CQDs合成条件。研究结果显示:优化后的CQDs合成条件为木质素磺酸钙质量浓度60 g/L,还原剂NaBH_(4)质量浓度50 g/L。利用透射电子显微镜(TEM)、红外光谱(FT-IR)、X射线光电子能谱(XPS)、紫外-可见光谱(UV-vis)和荧光光谱(FL)对CQDs的结构形貌及光学特性进行分析,结果显示:CQDs粒径小((9.5±0.5)nm)且分布均匀、无团聚现象,光学性能优异且荧光量子产率达12.4%。此外,基于CQDs探究不同银离子浓度对其荧光强度的影响,结果表明:CQDs对Ag^(+)具有较好的荧光识别性和灵敏度,在0~250μmol/L范围内CQDs荧光淬灭强度比值与Ag^(+)浓度呈线性关系(R^(2)=0.998),检测限可达525 nmol/L。同时,CQDs荧光选择性优异且表现出较低的细胞毒性,有望在生物传感和环境检测领域展现出潜在应用价值。

A New Carbon-based Optical Sensor for Detecting Silver Ion in Environmental Water

Lignin-based carbon quantum dots(CQDs) were prepared with calcium lignosulfonate as precursor by molecular self-assembly and ultrasound-assisted method at room temperature. The effects of calcium lignosulfonate and NaBH₄ on the fluorescence property of CQDs were studied, and the synthesis condition of CQDs was also optimized. The optimal preparation conditions were as follows: the mass concentration of calcium lignosulfonate was 60 g/L, the mass concentration of reducing agent NaBH₄ was 50 g/L. The structural morphology and optical properties of CQDs were confirmed by transmission electron microscopy(TEM), infrared spectroscopy(FT-IR), X-ray photoelectron spectroscopy(XPS), UV-visible spectroscopy(UV-vis), and fluorescence spectroscopy(FL). The experimental results showed that CQDs had small particle size((9.5±0.5)nm), uniform distribution, no agglomeration phenomenon, excellent optical properties, and fluorescence quantum yield of 12.4%. In addition, CQDs were used to investigate the effect of different silver ion concentrations on the fluorescence intensity. The results showed that CQDs had good fluorescence recognition and sensitivity to Ag⁺, with a linear detection range(R²=0.998) of 0-250 μmol/L and a detection limit of 525 nmol/L. Meanwhile, CQDs fluorescence showed excellent selectivity and low cytotoxicity, which was expected to show potential application value in biosensing and environmental detection fields.