基于金属铱配合物的苯硫酚荧光探针的多功能化及应用

Base on intramolecular charge-transfer (ICT) pathway, which could efficiently regulate the fluorescence switch, we will design and synthesize some fluorescence metal-organic probes for detection of thiophenol using 2,4-dinitrobenzenesulfonyl as strongly electron-withdrawing moiety to protect amino groups of iridium complexes. The resulting sulfonamide of probes can be readily cleaved by a thiolate anion, derived from a thiol under basic conditions through the nucleophilic aromatic process. Moreover, in order to detect thiophenol in real water samples, living cells or aquatic animals (such as fishes), auxiliary ligands of these probes will be optimized by introducting various functional groups. Several galactose subunits will be used to decorate probes to enhance water solubility, thus detecting thiophenol in water samples and vitro/vivo in liver cells. Series of diarylethene derivatives with high photocyclization/photocycloreversion quantum yields will be connected to auxiliary ligands of iridium complexes to obtain mutli-responsively fluorescent probes. The obvious changes in their emission spectra induced by UV/vis lights can reduce influence of auto-fluorescence from organism when probes are utilized to detect thiophenol in living cells. Triarylamine groups will be introduced to auxiliary ligands to synthesize two-photon fluorescent probes, which will reduce the damages to living cells. We will bind triphenylphosphine (TPP) or trialkylamine groups to probes, which make compounds possess potential application of selectively stain of mitochondrial or lysosome respectively, thus further detecting thiophenol in/around this cellular organelles.

以吸电子性的2,4-二硝基苯磺酸保护金属铱配合物外围配体邻菲罗啉上的氨基，基于分子内电荷转移原理设计合成可选择性识别苯硫酚分子的比色型金属配合物荧光探针。对配合物的外围配体苯基吡啶进行多种功能化，扩展其应用范围，运用于检测环境及生物和细胞样品中的苯硫酚分子：引入水溶性基团，增强探针的水溶性，检测环境水样、水生生物（鱼）或者其他细胞中的苯硫酚分子；引入开（闭）环量子产率高及光反应敏感的二芳烯分子，合成双重响应荧光分子，可逆性的调控探针荧光变化从而减少检测生物样本中苯硫酚分子时自发荧光的影响；引入潜在双光子吸收的三芳胺基团合成低能量激发的双光子荧光探针，从而减少检测生物体内苯硫酚识别时对活体样品的损伤；引入三苯基膦或者三烷基氨等基团，可以对线粒体或者溶酶体等细胞器特异性的染色，从而可以特异性的识别某类细胞器附近及细胞器内的苯硫酚分子。

苯硫酚可作为一些药物、杀虫剂、聚合物的初始原料被运用于有机合成领域中，但苯硫酚的易挥发、味臭、高毒性使其成为生物与环境领域中的一类有害物质。建立相对简单、迅速的检测苯硫酚的手段具有一定的科学意义。其中荧光探针检测具有高灵敏、操作简单、检测迅速、对样品无损伤等优势。.本项目基于分子内电荷转移（Intramolecular charge-transfer，ICT）原理，通过化学修饰将吸电子性的2,4-二硝基苯磺酰基团引入到金属铱配合物从而调控配合物的荧光，设计合成四个可选择性识别苯硫酚分子的荧光探针：1)引入潜在双光子吸收的三芳胺基团合成荧光探针；2)引入光致变色二芳烯分子，合成双重响应荧光分子，拟以光刺激前后荧光的变化减少测试体系自发荧光的影响；3)引入水溶性基团，增强探针的水溶性；4)引入两个2,4-二硝基苯磺酰基团从而最大程度猝灭探针初始荧光。苯硫酚探针分子可定量检测水样中的苯硫酚，同时还能在PBS/人血清体系中识别苯硫酚探针。说明探针分子在环境和临床上具有一定的潜在应用价值。.作为拓展研究，设计合成了三个基于金属钌配合物的探针分子:1)其中有可用于检测次氯酸的荧光探针，测试体系不需要有机溶剂，而是纯PBS，同时可检测定量检测水体中的次氯酸分子；2)可检测金属离子Cu2+的金属钌荧光探针，与Cu2+2:1络合后，由于Cu2+的顺磁性，发生荧光淬灭，试纸条实验可以帮助我们仅利用简单的手提式紫外灯即可检测环境中的Cu2+；3)含有席夫碱结构的金属钌紫外可见探针分子，可以裸眼识别Cu2+和Fe3+，识别上述两种离子之后溶液颜色发生明显变化，同时试纸条实验可以帮助我们不借用其他仪器设备快速识别上述两种离子。