Herein, we revealed the excited-state intramolecular proton-transfer (ESIPT) process in 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and resorcinol based carbon dots. The dual-emissive fluorophore, 5,6-diethoxy-4,7-dihydroxyisoindoline-1,3-dione (DDD), is extracted from the products and identified as the main fluorescence origin of the carbon dots. A blue-to-green switching in the emission color of the DDD can be observed as the solution pH decreases and the polarity of the solvent increases. Versatile morphologies including disks, dots and fibers can be formed during the DDD self-assembly in different mediums. By virtue of ESIPT-induced sensitive fluorescence, we not only construct the fluorescent anti-counterfeiting platform based on photoswitching of carbon dots in response to ammonia vapor and dimethyl sulfoxide stimuli, but also develop the picric acid sensing system with high selectivity and sensitivity.

在此，我们揭示了 2,3-二氯-5,6-二氰基-对苯醌 (DDQ) 和间苯二酚基碳点中的激发态分子内质子转移 (ESIPT) 过程。双发射荧光团 5,6-diethoxy-4,7-dihydroxyisoindoline-1,3-dione (DDD) 从产品中提取出来并被确定为碳点的主要荧光来源。随着溶液 pH 值的降低和溶剂极性的增加，可以观察到 DDD 发射颜色从蓝到绿的转换。在不同介质中的 DDD 自组装过程中，可以形成包括圆盘、点和纤维在内的多种形态。凭借ESIPT诱导的灵敏荧光，我们不仅构建了基于碳点响应氨气和二甲亚砜刺激光开关的荧光防伪平台，