【作者】 孟庆涛；

【导师】 段春迎； 周硼；

【作者基本信息】 大连理工大学 ， 精细化工， 2011， 博士

【摘要】 荧光分子探针具有高选择性、高灵敏度和快速便捷等特点,近些年被广泛应用于分子、离子的识别以及生物成像。本论文将荧光探针固载到载体材料上,成功地应用于环境和生命体系中重金属离子的检测,并提升了载体材料对环境中重金属离子的吸附能力,是合成对重金属离子等污染物具有快速检测、高效吸附以及荧光成像等多功能用途的实用型新材料的一种有效方法。设计合成了3种固载了荧光分子探针的SBA-15杂化材料：SBA-P1、SBA-P2和SBA-RT。SBA-P1在水体系中通过荧光淬灭的方式选择性地识别Hg2+,检测限为200ppb；而荧光材料SBA-P2在水体系中通过荧光淬灭的方式选择性地识别Cu2+,检测限为1 ppb,低于国家饮用水标准所规定的1 ppm的最高允许含量。由于受SBA-15介孔孔道内的微观尺寸空间效应的影响,Cu2+荧光探针固载到SBA-15材料后,其荧光光谱出现蓝移现象,选择性和灵敏度也有所提高；材料SBA-RT在纯水体系中可以选择性地识别Cr3+,加入20μM的Cr3+后,荧光增强了8倍,同时材料由无色变为粉红色。对Cr3+的检测限为50ppb。荧光分子探针固载到SBA-15后,表现出与有机小分子探针不同的光谱响应以及较高的选择性和灵敏度。荧光探针功能化的SBA.15材料对Hg2+、Cu2+和cr3+的吸附能力较SBA-15增强了6-7倍,且材料都具有可再生能力,并可应用于不同水源样品中。SBA-P2和SBA-RT还成功应用于活体组织和细胞内Cu2+和Cr3+的荧光成像。以水溶性的(L-CS)和高密度的(H-CS)壳聚糖为载体材料,设计合成了荧光分子探针改性的功能材料：H-CS-RB、L/H-CS-Fluo和L/H-CS-Cb。荧光材料H-CS-RB可以在水体系中通过荧光和“显色”的方法选择性地识别Hg2+,检测限可在10 ppb以下。水溶性的荧光材料L-CS-Fluo和L-CS-Cb则可在Tris-HCl缓冲溶液中通过荧光淬灭的方式选择性地识别Fe3+,检测限分别为0.2ppm和0.6ppm。同时为了研究荧光材料与重金属离子的作用机理,又合成了由壳聚糖单体氨基葡萄糖衍生的小分子探针：AG-RB、AG-Fluo和AG-Cb,这些小分子探针展现了与荧光材料相同的识别性能。由于氨基葡萄糖和低分子量壳聚糖(L-CS)良好的水溶性以及生物兼容性,AG-RB、L-CS-Fluo与L-CS-Cb分别成功地实现了对活体细胞内Hg2+和Fe3+的荧光成像。不溶性的荧光材料H-CS-RB,H-CS-Fluo和H-CS-Cb吸附Hg2+和Fe3+的能力相对于未经荧光探针改性的高密度壳聚糖(H-CS)均提高了近一倍,并且吸附过程中伴随着材料颜色的的明显变化。研究还发现壳聚糖荧光材料也可在不同水源样品中应用。设计合成了两个新型的基于罗丹明衍生物的NO荧光探针：RB-TP和RB-Py。在Cu2+存在下,两个荧光探针都能选择性地识别水中的NO。在NO的识别过程中,Cu2+不仅诱导化合物RB-TP和RB-Py水解为罗丹明水合肼(RB-NH2);而且配合物中的Cu2+作为氧化活性中心,还能将加入的NO氧化成NO+。NO+进而与RB-NH2反应生成亚硝酰化的开环罗丹明结构,从而表现为荧光和紫外的明显增强,20分钟左右达到平衡,其中探针RB-TP和RB-Py的荧光分别增加了9.5倍和6.5倍,同时溶液由无色变为红色。检测限分别为5 nM和20 nM。生物体内的其他活性物种,如1O2、NO2-、NO3-、ONOO-、H2O2和CIO-均没有明显的干扰。RB-TP和RB-Py还应用到活体细胞内NO的荧光成像。更多还原

【Abstract】 During the past decade, fluorescent probes have become an important research field of supramolecular chemistry and have attracted great attention because of their simplicity, high selectivity and sensitivity in fluorescent assays. Furthermore, improved sensing materials can be achieved by immobilizing fluorescent probes onto carrier materials, and will have more comprehensive applications.Three fluorescent hybrid materials were synthesized by immobilization of fluorescence probes within the channels of the SBA-15. Hybrid material SBA-P2 exhibits several different properties compared to the free fluorescent probe, such as higher selectivity and blue-shift of the fluorescence spectra due to special spatial environment in the channels of the SBA-15. SBA-P2 was able to selectively detect Cu2+ with a detection limit for Cu2+ of ca.0.65 ppb under optimized conditions. The adsorption of SBA-P2 for Cu2+ was dramatically enhanced due to the introduction of the Cu2+ fluorescence probes. Preliminary fluorescence microscopy experiments show that the SBA-P2 is a useful functionalized material for studying biological processes involving Cu2+ within living cells and living organisms. SBA-P1 can recognize and absorb Hg2+ with a high degree of selectivity among heavy metal ions in natural aqueous solution. The quenching fluorescence detection is also reversible by treating with EDTA/base. SBA-RT presents Cr3+-selective fluorimetric and colorimetric responses in aqueous solution. The fluorescence responses are reversible by treating with EDTA and do not vary over a broad pH range suitable for Cr3+ bioimaging application. Through isolating the metal ions within the mesopores of the silica, SBA-RT can extract Cr3+ from solution with only trace amounts remaining. The fluorescence images experiment also demonstrated the possibility of further application in monitoring Cr3+ in living cells and organisms.A series of grafted-probes chitosan materials were also synthesized. Fluorescent material H-CS-RB can selectively and sensitively detect Hg2+ by spectroscopic and "naked-eye" method in suspension solution with detection limit of 10 ppb. Fluorescent materials L-CS-Fluo, L-CS-Cb feature excellent water-solubility and biocompatibility and have been applied to selectively detect Fe3+ by fluorescent quenching method in environment and biological fields. The detection limit of L-CS-Fluo and L-CS-Cb for Fe3+ were 0.2 ppm and 0.6 ppm, respectively. Fluorescent molecule probes AG-Fluo, AG-Cb and AG-RB coupling the D-Glucosamine were also synthesized and exhibited consistent recognition abilities with corresponding fluorescent materials. Adsorption abilities of H-CS-RB, H-CS-Fluo and H-CS-Cb for Hg2+ and Fe3+ were more than doubled compared to free H-CS.Two rhodamine-based probes were designed and synthesized. Both RB-TP and RB-Py can detect NO with high selectivity and sensitivity in water assisted by Cu2+. RB-TP and RB-Py could be degraded to RB-NH2 as a result of Cu2+-promoted hydrolysis in water. Furthermore, the presence of NO will lead to reduction of Cu2+ to Cu+, and concomitant NO+ reacted with RB-NH2 generating the N-nitroso amide, opening the spirolactam ring of rhodamine B and evoking the emission and absorption increases. Fluorescence intensities of RB-TP and RB-Py showed 9.5-fold and 6.5-fold increases in 20 min, respectively. At the same time, the solutions turned pink to achieve "nake-eyed" detection. The detedction limit of RB-TP and RB-Py for NO were 5 nM and 20 nM, respectively. Other biologically relevant reactive species such as NO2-、NO3-、ONOO-、H2O2、1O2 and Clo- did not give any interference. Both of them have been applied to detect the intracellular NO by fluorescence imaging method.更多还原