Nanbedeh Saber, Faghihi Khalil
Department of Chemistry, Faculty of Science, Arak University, Arak, 38156-8-8349, Iran.
J Fluoresc. 2021 Mar;31(2):517-539. doi: 10.1007/s10895-020-02680-2. Epub 2021 Jan 16.
A new fluorescent mesoporous polyurethane (PU) (9) was synthesized by reaction between 2,2'-(methylenebis(4,1-phenylene))bis(5-isocyanatoisoindoline-1,3-dione) (Diisocyanate) (5) and 4,4',4″-((1,3,5-triazine-2,4,6-triyl)tris (azanediyl))triphenol (Triol, TO) (8) (molar ratio 3:2). PU was characterized by using FT-IR, H-NMR, XRD, UV-Vis, TGA, Nitrogen adsorption-desorption isotherm, BET, FE-SEM and Photoluminescence (PL) analyses. To the best of our knowledge, this is the first time that a fluorescent polyurethane has been made without the use of commercial fluorescent materials. PU has high fluorescent intensity and it is ultrafast (about few seconds), highly selective and sensitive turn-off fluorescent sensor for Fe ions. This chemosensor exhibited a wide concentration range of (10-250)×10 M Fe with quenching efficiency (η) 97.50%. Limit of detection (LOD), limit of quantification (LOQ) and quenching constant (Ksv) values were calculated 10.10×10 M, 30.60×10 M and 6919.31 M, respectively. Nitrogen doped carbon dots (N-doped CDs) as fluorescent nanoparticles and with the aim of improving Fe detecting were synthesized by microwave-assisted and using citric acid monohydrate (10) and ethylenediamine (11) as carbon and nitrogen sources, respectively. Fluorescent nanocomposites (FNCs) were prepared by using casting and in-situ methods. In both methods, two nanocomposites containing 5 and 10%w of N-doped CDs were prepared. FNCs were characterized by using FT-IR, UV-Vis, XRD, TGA, Nitrogen adsorption-desorption isotherm, BET, FE-SEM and PL analyses. All nanocomposites showed better thermal property and sensitivity and lower LOD values in lower concentration of Fe related to PU. Among them, FNC10in exhibited the best results as η, LOD, LOQ, Ksv reached 99.80%, 1.15×10 M, 3.48×10 M and 53,551.48 M, respectively.
通过2,2'-（亚甲基双（4,1-亚苯基））双（5-异氰酸酯异吲哚啉-1,3-二酮）（二异氰酸酯）（5）与4,4',4″-（（1,3,5-三嗪-2,4,6-三基）三（氮杂二亚基））三苯酚（三醇，TO）（8）（摩尔比3:2）反应合成了一种新型荧光介孔聚氨酯（PU）（9）。采用傅里叶变换红外光谱（FT-IR）、氢核磁共振（H-NMR）、X射线衍射（XRD）、紫外可见光谱（UV-Vis）、热重分析（TGA）、氮吸附-脱附等温线、比表面积测定（BET）、场发射扫描电子显微镜（FE-SEM）和光致发光（PL）分析对PU进行了表征。据我们所知，这是首次在不使用商业荧光材料的情况下制备出荧光聚氨酯。PU具有高荧光强度，是一种用于铁离子的超快（约几秒）、高选择性和高灵敏度的猝灭型荧光传感器。该化学传感器对铁离子的检测浓度范围为（10-250）×10⁻⁶ M，猝灭效率（η）为97.50%。计算出的检测限（LOD）、定量限（LOQ）和猝灭常数（Ksv）值分别为10.10×10⁻⁶ M、30.60×10⁻⁶ M和6919.31 M⁻¹。以一水柠檬酸（10）和乙二胺（11）分别作为碳源和氮源，通过微波辅助合成了氮掺杂碳点（N掺杂CDs）作为荧光纳米颗粒，旨在提高对铁的检测能力。采用流延法和原位法制备了荧光纳米复合材料（FNCs）。在这两种方法中，均制备了含5%和10%w N掺杂CDs的两种纳米复合材料。采用FT-IR、UV-Vis、XRD、TGA、氮吸附-脱附等温线、BET、FE-SEM和PL分析对FNCs进行了表征。与PU相比，所有纳米复合材料在较低铁浓度下均表现出更好的热性能和灵敏度以及更低的LOD值。其中，FNC10in表现出最佳结果，其η、LOD、LOQ、Ksv分别达到99.80%、1.15×10⁻⁶ M、3.48×10⁻⁶ M和53551.48 M⁻¹。
