Cholesterol modified OPE functionalized film: fabrication, fluorescence behavior and sensing performance
作者:Hongyue Wang、Gang He、Xiangli Chen、Taihong Liu、Liping Ding、Yu Fang
DOI:10.1039/c2jm16637b
日期:——
A novel oligo(p-phenyleneethynylene) with cholesterol on its side chains (CHOL-OPE) was designed and synthesized. Film 1 and Film 2 were fabricated by immobilizing, separately, the oligomer as prepared and its control, OPE, which contains no side chains, on glass plate surfaces via utilization of a self-assembled monolayer (SAMs) technique. Fluorescence studies revealed that the profile of the fluorescence emission spectrum of Film 1 is dependent upon the composition of a mixture of THF and water. In contrast, Film 2 shows no such effect. Sensing performance studies demonstrated that the fluorescence of Film 1 is super-sensitive to the presence of 2,4,6-trinitrophenol (picric acid, PA), and sensitive to 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT) and nitrobenzene (NB) in the aqueous phase, whereas the nitroaromatics (NACs) as studied show little effect on the fluorescence emission of Film 2. The results from fluorescence quenching studies and the fact that copper salts (copper nitrate and copper acetate) show no detectible effect on the fluorescence emission of Film 1 show that the oligomer and the short linker, connecting the oligomer and the substrate, of the CHOL-OPE functionalized film may adopt a compact structure. Interestingly, the sensing process is fully reversible and free of interference from commonly found compounds, including methanol, THF, toluene, dichloromethane, ammonia, HCl, NaOH, NaCl, copper salts and seawater, etc. Fluorescence lifetime measurements revealed the static nature of the quenching process. The superior sensing performance of Film 1 for the analytes in the aqueous phase guarantees that the film may have the potential to be developed into a sensor device for the detection of PA and other NACs in groundwater.
设计并合成了一种带有胆固醇侧链的新型寡聚(对苯乙炔) (CHOL-OPE)。通过利用自组装单层(SAMs)技术,分别将合成的CHOL-OPE和不含侧链的控制样品OPE固定在玻璃板上,制备了Film 1和Film 2。荧光研究表明,Film 1的荧光发射光谱特征取决于THF和水的混合物组成,而Film 2则没有这种效应。传感性能研究表明,Film 1的荧光对水相中存在的2,4,6-三硝基苯酚(苦味酸,PA)超敏感,对2,4,6-三硝基甲苯(TNT)、2,4-二硝基甲苯(DNT)和硝基苯(NB)敏感,而所研究的硝基芳烃(NACs)对Film 2的荧光发射几乎没有影响。荧光猝灭研究的结果以及铜盐(硝酸铜和醋酸铜)对Film 1荧光发射没有可检测效应的事实表明,CHOL-OPE功能化膜中的寡聚物和连接寡聚物与基底的短连接子可能采取了紧凑的结构。有趣的是,传感过程完全可逆,并且不受常见化合物如甲醇、THF、甲苯、二氯甲烷、氨、HCl、NaOH、NaCl、铜盐和海水等的干扰。荧光寿命测量揭示了猝灭过程的静态性质。Film 1对水相中分析物的出色传感性能保证了该膜有可能被开发成一种传感器设备,用于检测地下水中的PA和其他NACs。