Carbon quantum dots (CQDs) with semiconductor-like properties have received considerable attention because of their unique photoelectric properties and electron transfer ability. However, the preparation of highly crystalline CQDs with strong fluorescence (FL) emission by the room temperature (RT) synthesis is a challenging task. Herein, we develop a highly-efficient RT synthesis strategy based on the Schiff base condensation reaction for preparing the fluorine-doped CQDs (F-CQDs) with good crystallinity. The as-prepared F-CQDs show strong blue FL emission with a high quantum yield of 39%, which is the highest values yet recorded for carbon dots prepared by RT synthesis. Moreover, the F-CQDs can be used for sensitive tetracycline sensing based on inner filter effect. The FL intensity ratio (F₀/F) of the F-CQDs is proportional to the concentration of tetracycline in the range of 0.1–25 μM with the limit of detection of 85 nM. This sensitive assay has a good application prospect for tetracycline detection in the complex matrixes because of its simplicity and sensitivity.

具有类半导体特性的碳量子点（CQD）由于其独特的光电特性和电子转移能力而受到广泛关注。但是，通过室温（RT）合成制备具有强荧光（FL）发射的高结晶CQD是一项艰巨的任务。在本文中，我们开发了基于席夫碱缩合反应的高效RT合成策略，以制备具有良好结晶度的掺氟CQD（F-CQD）。所制备的F-CQD显示出强烈的蓝色FL发射，具有39％的高量子产率，这是通过RT合成制备的碳点迄今为止所记录的最高值。此外，F-CQD可以基于内部滤波器效应用于灵敏的四环素感测。FL强度比（F ₀ /F -CQD的F）与四环素的浓度成正比，范围为0.1–25μM，检出限为85 nM。这种灵敏的测定方法具有简便性和灵敏性，因此在复杂基质中四环素的检测方面具有良好的应用前景。