School of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.
Department of Analytical Chemistry for Pharmaceuticals, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.
Anal Chim Acta. 2022 Jul 18;1217:340024. doi: 10.1016/j.aca.2022.340024. Epub 2022 May 30.
Copper (II) is one of the most important metal ions for the human body that act as a catalytic cofactor for many metalloenzymes and proteins, and its homeostasis disruption could lead to many neurological diseases. The reported probes for Cu (II) determination are mostly based on fluorescence quenching mechanism, which provides low precision and reliability. In the present work, a turn-on fluorescence probe, (Z)-1-[2-oxo-2-[2-[1-oxoaceanthrylen-2 (1H)-ylidene]hydrazinyl]ethyl]-pyridinium (OAHP), for highly selective detection of Cu was developed. Hydrazide moiety of OAHP quenches probe fluorescence; however, upon its reaction with Cu, oxidative cleavage of the hydrazide moiety and intramolecular cyclization occurs, forming oxadiazole derivative with strong fluorescent properties. In this context, OAHP displayed significant fluorescence enhancement with increasing levels of Cu. OAHP could detect Cu selectively with a detection limit of 18 nM (1.1 ppb). This is the first report for a probe that uses the ability of Cu to induce oxidative decomposition of hydrazide with intramolecular cyclization, and it showed exceptional selective performance and exquisite sensitivity. Next, the method was applied successfully for monitoring Cu in tap water samples with good accuracy (found% of 95.8-101.5%) and precisions (RSD<10%). Finally, OAHP was successfully applied for imaging Cu in living cells, and this result indicates the potential of OAHP for selective detection of Cu in complicated matrices.
铜（II）是人体最重要的金属离子之一，它作为许多金属酶和蛋白质的催化辅助因子，其体内平衡的破坏会导致许多神经疾病。目前报道的用于测定 Cu（II）的探针主要基于荧光猝灭机制，其提供的精度和可靠性较低。在本工作中，设计并合成了一种用于高选择性检测 Cu 的荧光开环探针（Z）-1-[2-氧代-2-[2-[1-氧代吖啶-2（1H）-亚基]肼基]乙基]吡啶𬭩（OAHP）。OAHP 的酰腙部分猝灭探针的荧光；然而，当与 Cu 反应时，酰腙部分发生氧化裂解和分子内环化，形成具有强荧光性质的噁二唑衍生物。在这种情况下，随着 Cu 水平的增加，OAHP 显示出显著的荧光增强。OAHP 可以选择性地检测 Cu，检测限为 18 nM（1.1 ppb）。这是第一个使用 Cu 诱导酰腙的氧化分解与分子内环化的能力的探针的报告，它表现出出色的选择性和灵敏度。接下来，该方法成功应用于自来水样品中 Cu 的监测，具有良好的准确性（回收率为 95.8-101.5%）和精密度（RSD<10%）。最后，OAHP 成功应用于活细胞中 Cu 的成像，这一结果表明 OAHP 具有在复杂基质中选择性检测 Cu 的潜力。
