Danquah Michael K, Wang Shan, Wang Qianyou, Wang Bo, Wilson Lee D
Department of Chemistry, University of Saskatchewan 110 Science Place Saskatoon Saskatchewan S7N 5C9 Canada
Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Material, Key Laboratory of Cluster Science, Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology 5 South Zhonguancun Street Beijing 100081 P. R. China.
RSC Adv. 2019 Mar 11;9(14):8073-8080. doi: 10.1039/c8ra06192k. eCollection 2019 Mar 6.
Permanent porosity plays a key role in fluorescent-based polymers with "on-off" emissive properties due to the role of guest adsorption at accessible fluorophore sites of the polymer framework. In particular, we report on the design of a porous fluorescent polymer (FL-PFP) composed of a covalently cross-linked ternary combination of β-cyclodextrin (β-CD), 4,4'-diisocyanato-3,3'-dimethyl biphenyl (DL) and tetrakis(4-hydoxyphenyl)ethene (TPE). The textural properties of FL-PFP were evaluated by the gas uptake properties using N and CO isotherms. The BET surface area estimates according to N uptake ranged from 100-150 m g, while a lower range of values (20-30 m g) was estimated for CO uptake. Model nitroarenes such as trinitrophenol (TNP) and nitrobenzene (NB) were shown to induce turn-off of the fluorescence emission of the polymer framework at concentrations near 50 nM with 50% fluorescence quenching upon TNP adsorption and detection. The strong donor-acceptor interaction between the nitroarenes and the TPE reporter unit led to fluorescence quenching of FL-PFP upon nitroarene adsorption. The fluorescence lifetime () for FL-PFP ( = 3.82 ns) was obtained along with a quantum yield estimate of 0.399 relative to quinine sulphate. The β-CD terpolymer reported herein has significant potential for monitoring the rapid and controlled detection of nitroarenes (TNP and NB) in aquatic environments and other complex media.
由于客体在聚合物骨架可及荧光团位点上的吸附作用，永久孔隙率在具有“开-关”发射特性的荧光基聚合物中起着关键作用。特别地，我们报道了一种多孔荧光聚合物（FL-PFP）的设计，它由β-环糊精（β-CD）、4,4'-二异氰酸酯-3,3'-二甲基联苯（DL）和四（4-羟基苯基）乙烯（TPE）通过共价交联形成三元组合。通过使用N₂和CO₂等温线的气体吸附性质来评估FL-PFP的织构性质。根据N₂吸附估算的BET表面积范围为100 - 150 m²/g，而根据CO₂吸附估算的值范围较低（20 - 30 m²/g）。三硝基苯酚（TNP）和硝基苯（NB）等模型硝基芳烃在浓度接近50 nM时可使聚合物骨架的荧光发射猝灭，TNP吸附和检测时荧光猝灭50%。硝基芳烃与TPE报告单元之间强烈的供体-受体相互作用导致硝基芳烃吸附时FL-PFP的荧光猝灭。获得了FL-PFP的荧光寿命（τ = 3.82 ns）以及相对于硫酸奎宁的量子产率估计值0.399。本文报道的β-CD三元共聚物在监测水生环境和其他复杂介质中硝基芳烃（TNP和NB）的快速和可控检测方面具有巨大潜力。
