Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi, 435002, China.
Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Jianghan University, Wuhan, 430056, Hubei, China.
Mikrochim Acta. 2024 Oct 25;191(11):698. doi: 10.1007/s00604-024-06786-3.
Nitrogen-doped silicon quantum dots (N-SiQDs) with a quantum yield of up to 37.8% were simply synthesized using inexpensive and readily available silica as the silicon source. Based on the internal filter effect (IFE), both oxytetracycline (OTC) and tetracycline (TC) can effectively and rapidly quench the fluorescence of N-SiQDs at 380 nm. However, interestingly, the accompanied formation of a new complex of OTC with N-SiQDs could emit fluorescence at 505 nm, resulting in a gradual color change of the sensor from blue to yellow under the irradiation of 365 nm UV lamp. Thus, a visual semi-quantitative detection of OTC was realized. In contrast, based on the aggregation-induced luminescence (AIE) effect, chlortetracycline (CTC) linearly enhanced the fluorescence intensity of N-SiQDs, which can effectively reduce other interfering signals, and can significantly improve the sensitivity and selectivity. Hence, a low limit of detection of 47 nM for CTC was obtained. On account of the three distinctly different phenomena and mechanisms of N-SiQDs sensor exhibited towards OTC, TC, and CTC, a novel sensing method for discriminating and selectively measuring OTC, TC, and CTC in food was developed.
采用廉价易得的硅源二氧化硅简单合成了量子产率高达 37.8%的氮掺杂硅量子点（N-SiQDs）。基于内滤效应（IFE），氧四环素（OTC）和四环素（TC）均可有效快速猝灭 N-SiQDs 在 380nm 处的荧光。然而，有趣的是，伴随形成的 OTC 与 N-SiQDs 的新络合物在 505nm 处发射荧光，导致传感器在 365nm 紫外灯下的颜色逐渐由蓝变黄。因此，实现了 OTC 的可视化半定量检测。相比之下，基于聚集诱导发光（AIE）效应，金霉素（CTC）线性增强了 N-SiQDs 的荧光强度，可以有效降低其他干扰信号，并显著提高了检测的灵敏度和选择性。因此，获得了 CTC 的低检测限为 47nM。鉴于 N-SiQDs 传感器对 OTC、TC 和 CTC 表现出三种截然不同的现象和机制，开发了一种用于区分和选择性测量食品中 OTC、TC 和 CTC 的新型传感方法。
