AbstractSilicon nanoparticles (SiNPs) modified with Eu(III) were synthesized and are shown to be a viable ratiometric fluorescent probe for tetracycline antibiotics. SiNPs/Eu under 405 nm excitation display two emissions, viz. a strong cyan colored fluorescence peaking at 497 nm and a weak pink fluorescence peaking at 622 nm. On addition of tetracyclines (chlortetracycline, tetracycline, doxycycline), the fluorescence at 497 nm is reduced, while the one at 622 nm is increased. Thus, the visible color of fluorescence changes from cyan to pink. This was exploited to design ratiometric fluorometric method for detecting tetracyclines. The method has a limit of detection that is lower by a factor of about 1000 when compared to the use of SiNPs only. A test paper was prepared with the SiNPs/Eu and then applied for the visual semi-quantitative detection of tetracyclines. With the addition of tetracyclines, the test paper exhibited a dosage-sensitive color conversion from cyan to pink with a visually discernible scale as low as 0.4 μM. Graphical abstractTetracyclines decrease the fluorescence at 497 nm of europium (III) modified silicon nanoparticles (SiNPs/Eu) due to the inner filter effect and increase the one at 622 nm due to an antenna effect. Thus the fluorescence color of SiNPs/Eu changes from cyan to pink. Based on this color switch, a ultrasensitive and visual determination strategy for tetracyclines is proposed.

中文翻译：

---

铕 (III) 改性的有机硅纳米粒子用于通过荧光颜色开关超灵敏目测测定四环素

摘要合成了用 Eu(III) 修饰的硅纳米粒子 (SiNPs)，并被证明是一种可行的四环素抗生素比率荧光探针。SiNPs/Eu 在 405 nm 激发下显示两种发射，即。强烈的青色荧光在 497 nm 处达到峰值，而粉红色的弱荧光在 622 nm 处达到峰值。添加四环素（金霉素、四环素、强力霉素）后，497 nm 处的荧光减弱，而 622 nm 处的荧光增强。因此，荧光的可见颜色从青色变为粉红色。这被用来设计检测四环素的比率荧光法。与仅使用 SiNP 相比，该方法的检测限降低了约 1000 倍。用SiNPs/Eu制备试纸，用于四环素的视觉半定量检测。添加四环素后，试纸表现出从青色到粉红色的剂量敏感颜色转换，视觉上可辨别的比例低至 0.4 μM。图形摘要四环素由于内部过滤效应降低了铕 (III) 改性硅纳米粒子 (SiNPs/Eu) 在 497 nm 处的荧光，并由于天线效应增加了 622 nm 处的荧光。因此，SiNPs/Eu 的荧光颜色从青色变为粉红色。基于这种颜色开关，提出了四环素的超灵敏和视觉测定策略。4 微米。图形摘要四环素由于内部过滤效应降低了铕 (III) 改性硅纳米粒子 (SiNPs/Eu) 在 497 nm 处的荧光，并由于天线效应增加了 622 nm 处的荧光。因此，SiNPs/Eu 的荧光颜色从青色变为粉红色。基于这种颜色开关，提出了四环素的超灵敏和视觉测定策略。4 微米。图形摘要四环素由于内部过滤效应降低了铕 (III) 改性硅纳米粒子 (SiNPs/Eu) 在 497 nm 处的荧光，并由于天线效应增加了 622 nm 处的荧光。因此，SiNPs/Eu 的荧光颜色从青色变为粉红色。基于这种颜色开关，提出了四环素的超灵敏和视觉测定策略。