Abstract

An ethyl 3-aminobenzo[b]thiophene-2-carboxylate derived ratiometric Schiff base fluorescent sensor R was devised and synthesized. R exhibited a highly sensitive and selective ratiometric response to In³⁺ in DMF/H₂O tris buffer solution. R exhibited a colorimetric/fluorescent dual-channel response to In³⁺. More importantly, R can distinguish In³⁺ from Ga³⁺ and Al³⁺ in less than 5 min. R exhibited a good linear correlation with the concentration of In³⁺ in the 5–25 μM range and the limit of detection for In³⁺ was found to be 8.36 × 10^–9 M. According to the job`s plot and MS spectra, R formed a complex with In³⁺ at 1:2 with a complexation constant of 8.24 × 10⁹ M². Based on Gaussian theory calculations, the response mechanism of R to In³⁺ can be explained by photo-induced electron transfer (PET) and intramolecular charge transfer (ICT) mechanisms. In addition, R can be used for the detection of indium in tap water with satisfactory recoveries. Meanwhile, R displayed a linear relationship to micromolar concentrations (0-50 μM) of Pb²⁺ and recognized Pb²⁺ in a ratiometric response with a detection limit of 8.3 × 10^–9 M.

中文翻译：

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3-氨基苯并[b]噻吩-2-甲酸乙酯衍生的比率希夫碱荧光传感器用于识别 In3+ 和 Pb2+

摘要

设计并合成了3-氨基苯并[b]噻吩-2-甲酸乙酯衍生的比例希夫碱荧光传感器R。R对 DMF/H _{2 O tris 缓冲溶液中的 In} ³⁺表现出高度灵敏和选择性的比率响应。R对 In ³⁺表现出比色/荧光双通道响应。更重要的是，R可以在不到5分钟的时间内将In ³⁺与Ga ³⁺和Al ^{3+区分开。}R在 5–25 μM 范围内与 In ³⁺浓度呈现良好的线性相关性，In ³⁺的检测限为 8.36 × 10 ^–9  M。根据作业图和 MS 谱图，R与In ³⁺以1:2形成络合物，络合常数为8.24×10 ⁹ M ²​​ 。基于高斯理论计算，R对In ³⁺的响应机制可以通过光致电子转移（PET）和分子内电荷转移（ICT）机制来解释。此外，R还可用于自来水中铟的检测，回收率令人满意。同时，R与Pb ²⁺的微摩尔浓度（0-50 μM）呈线性关系，并以比例响应识别Pb ²⁺，检测限为8.3 × 10 ^–9  M。