1,3-Dichloro-7-hydroxy-9,9-dimethyl-2(9H)-acridone (DDAO) is an excellent near-infrared fluorescent dye with near-infrared emission, low pKa (≈5.0), high water solubility and high quantum yield (Φ＝0.39), which has attracted much attention in recent years in the field of fluorescent probes. The researches prove that the fluorescent probes designed and synthesized based on this dye can work in mild aqueous solutions, and have excellent sensing performance, such as rapid reaction, high selectivity and sensitivity, low detection limit and obvious colorimetric signal change. In addition, the low cytotoxicity of this class of probes is of significant application for the detection of living cells and organisms. The research progress of fluorescent probes based on DDAO and its derivatives, mainly including the molecular design, action mechanism and application of probes in the recognition and detection of biological enzymes, reactive oxygen species, reactive nitrogen species, proteins and Pd 0 , is reviewed, and the development prospect of this type of fluorescent probes is prospected. Keywords 1,3-dichloro-7-hydroxy-9,9-dimethyl-2(9H)-acridone (DDAO); fluorescent probe; near infrared; detection 荧光探针是一种结合了分子识别和荧光技术的生 物传感器, 通常由荧光团和识别基团通过连接臂以共价 键的形式连接而成. 对特定的分析物或环境响应时, 探 针自身的荧光性质会发生改变, 以此作为检测和识别的 信号 [1][2] . 与传统的检测方法(电位法、极谱法或比色法) 相比 [3][4][5] , 荧光探针具有操作简单、 选择性好、 灵敏度高、 检测范围广、响应速度快以及对样品损伤小等优点 [6][7] , 已经被成功应用于生物医学、生命科学及环境科学等领 域 [8][9] . 荧光探针不仅可以检测阳离子和阴离子 [10][11][12] , 还 可以检测活性氧 [13][14][15] 及硫化氢等小分子化合物 [16][17][18] , 近 年来检测生物酶 [19] 和细菌 [20][21] 等生物活性物质的荧光 探针也越来越多. 最值得一提的是, 由于部分荧光探针 具有良好的生物相容性、高灵敏度、无创性、稳定的发 射特性和实时成像等优点, 使得基于荧光探针的生物成 像技术发展迅速, 现在已成为可视化多种生理和病理过 程的有力工具 [22][23][24] . 但令人遗憾的是, 发射波长小于 600 nm 的荧光探针在进行活体荧光成像时组织穿透性 差, 会产生组织损伤, 同时受到机体自发荧光的干扰,
