Luminescent materials, particularly those with tunable wavelengths, are gaining considerable attention owing to their advanced applications in optoelectronic devices, fluorescent probes and sensors etc. Among all species studied, luminogens without typical chromophores have been gaining increasing attention. The related studies have been mainly focused on polymers with functional groups, such as aliphatic tertiary amine, carbonyl, ester, hydroxyl, amide, imide etc. Here we report a new type of nonconventional fluorescent emitter, fully water-soluble aliphatic amide salt. By simply blending methanol solution of ethylene diamine with that of succinic acid, the aliphatic amide salt (PA24S) was precipitated out, and identified through a series of advanced testing. Both the salt PA24S and the polyamide showed fluorescent emission as solid powders and in their solutions. The emission behavior of PA24S was studied with regard to concentration, pH, temperature and non-solvent fraction. It was concluded that the emission was owing to the formation of molecule clusters, and confirmed by UV-vis absorption, cluster size measurement and NMR test. It was also demonstrated that Cu²⁺ was an effective quenching agent with good selectivity. The cytotoxicity assay demonstrated that PA24S was non-toxic to HeLa cell, and suitable for cell imaging. Combined with selective quenching of Cu²⁺, PA24S is successfully used for Cu²⁺ detection and monitoring. This work provides therefore a novel type of luminogen of great potential applications in biological fields, featured by its easiness to make, high water solubility and broad emission in dilute solution and at solid state.

发光材料，特别是具有可调波长的发光材料，由于其在光电器件，荧光探针和传感器等方面的先进应用而受到了广泛的关注。在所有研究的物种中，没有典型发色团的发光剂受到越来越多的关注。相关研究主要集中在具有官能团的聚合物上，例如脂族叔胺，羰基，酯，羟基，酰胺，酰亚胺等。在这里，我们报道了一种新型的非常规荧光发射体，即完全水溶性的脂族酰胺盐。通过简单地将乙二胺的甲醇溶液与琥珀酸的甲醇溶液混合，沉淀出脂肪族酰胺盐（PA24S），并通过一系列高级测试进行鉴定。盐PA24S和聚酰胺均以固体粉末及其溶液形式显示荧光发射。研究了PA24S的发射行为，涉及浓度，pH，温度和非溶剂分数。结论是，发射是由于分子簇的形成，并通过紫外可见吸收，簇尺寸测量和NMR测试证实。还证明了铜²⁺是一种有效的淬灭剂，具有良好的选择性。细胞毒性试验表明，PA24S对HeLa细胞无毒，适用于细胞成像。结合对Cu ^2+的选择性淬灭，PA24S已成功用于Cu ^2+的检测和监测。因此，这项工作提供了一种新型的发光剂，其在生物领域具有巨大的潜在应用，其特点是易于制造，高水溶性以及在稀溶液和固态下的广泛发射。