Ascorbic acid (AA), an essential nutrient in the human body, is an antioxidant that protects the body from the threat of free radicals. The sensitive, efficient and rapid detection of AA has far-reaching significance in human health, biomedicine and food-related science. Herein, pyromellitic acid (H₄btec) and nicotinic acid (Hntca) were used as ligands to synthesize a novel terbium-based coordination polymer ([Tb(Hbtec)(Hntca)(H₂O)₃]·H₂O) under solvothermal conditions, which was interlaced by coordination bonds and hydrogen bonds to form an infinitely extended three-dimensional supramolecular structure. The two ligands as “antenna molecules” could effectively sensitize Tb³⁺ luminescence. The research results showed that AA was selectively recognized by the complex through significant fluorescence quenching response, and it had excellent detection sensitivity (the detection limit is 0.8 μM) and anti-interference ability. The sensor system was successfully applied to the detection of AA in practical samples, so it was expected to be sensitive and efficient AA sensor. In addition, the sensing mechanism was analyzed in detail by the combination of characterization method and density functional theory (DFT), which was attributed to the absorption competition of excitation light energy and the photoinduced electron transfer (PET) process.

抗坏血酸 (AA) 是人体必需的营养素，是一种抗氧化剂，可保护身体免受自由基的威胁。AA的灵敏、高效、快速检测在人类健康、生物医学和食品相关科学领域具有深远意义。在此，均苯四酸（H ₄ btec）和烟酸（Hntca）作为配体合成了一种新型的铽基配位聚合物（[Tb(Hbtec)(Hntca)(H ₂ O) ₃ ]·H ₂ O)，在溶剂热条件下，由配位键和氢键交织形成无限延伸的三维超分子结构。两个配体作为“天线分子”可以有效地敏化Tb ³⁺发光。研究结果表明，AA通过显着的荧光猝灭反应被络合物选择性识别，具有优良的检测灵敏度（检测限为0.8 μM）和抗干扰能力。该传感器系统成功应用于实际样品中AA的检测，有望成为一种灵敏高效的AA传感器。此外，通过表征方法和密度泛函理论（DFT）相结合，详细分析了传感机制，这归因于激发光能的吸收竞争和光致电子转移（PET）过程。