Two new Schiff bases, (()-N′-(2-hydroxybenzylidene)-5-(thiophene-2-yl)isoxazole-3-carbohydrazide) and (()-N′-(3-ethoxy-2-hydroxybenzylidene)-5-(thiophene-2-yl)isoxazole-3-carbohydrazide), have been designed and synthesized as chemosensors for distinct recognition of Ga and Fe ions. demonstrated a prominent “turn on” response characterized by clear distinguished fluorescence when coordination with Ga ions in the DMSO/HO buffer solution. In comparison, also showed “turn on” response of blue fluorescence which was more selective and sensitive than that of due to the steric hindrance of ethoxy group of . The newly formed complexes -Ga and -Ga may act as selective “turn-off” fluorescent probes towards Fe ions. Limits of detection of and towards Ga ions were 7.8809 × 10 M and 2.6277 × 10 M, respectively. Limits of detection of -Ga and -Ga towards Fe ions were 8.6562 × 10 M and 3.3764 × 10 M, respectively. The molar ratio of the complex between the sensor and Ga or Fe ions were all 1:2 determined through Job's Plot, mass spectrometry, and theoretical calculations. Both sensors were utilized for the determination of target ions in environment water samples, and the portable paper sensors for detecting Ga ions have been successfully developed.

中文翻译：

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两种源自 5-(噻吩-2-基)异恶唑的新型席夫碱作为“Off-On-Off”荧光传感器用于连续检测 Ga3+ 和 Fe3+ 离子的比较研究

两种新的席夫碱，(()-N′-(2-羟基亚苄基)-5-(噻吩-2-基)异恶唑-3-碳酰肼)和(()-N′-(3-乙氧基-2-羟基亚苄基) -5-(噻吩-2-基)异恶唑-3-碳酰肼)已被设计和合成为化学传感器，用于明显识别 Ga 和 Fe 离子。当与 DMSO/H2O 缓冲溶液中的 Ga 离子配位时，表现出显着的“开启”响应，其特征是清晰的荧光。相比之下，由于乙氧基的空间位阻，也显示出蓝色荧光的“开启”响应，比 的选择性和灵敏性更高。新形成的配合物-Ga和-Ga可以充当针对Fe离子的选择性“关闭”荧光探针。 Ga 离子和 Ga 离子的检测限分别为 7.8809 × 10 M 和 2.6277 × 10 M。 -Ga 和 -Ga 对 Fe 离子的检测限分别为 8.6562 × 10 M 和 3.3764 × 10 M。通过Job's Plot、质谱和理论计算确定传感器与Ga或Fe离子之间的络合物的摩尔比均为1:2。两种传感器均用于环境水样中目标离子的测定，并成功开发了用于检测Ga离子的便携式纸质传感器。