Synthesis And Application Of Multifunctional Perylenediimide Derivatives

Multi-functional fluorescent material is a combined subject taking advantages of the highly sensitive fluorescent materials and practical functional materials. Due to excellent optical, thermal and chemical stability,perylene diimide derivatives (PDIs) have been widely used in the field of optoelectronics, dyes, self-assembly and bioimaging. These excellent properties made PDIs a kind of muti-functional fluorescent materials. PDI can be multi-functionalized by chemical modification with small functional groups or polymers at the imide/bay positions. Compared with polymer modification,small functional groups modified PDIs are more simple, flexible and accurate.In this paper, design, synthesis and chemical modification of multi-functional PDIs were reported. With specific responsive groups, these PDIs were further applied in specific molecule/ion detection, bioimaging, gene carrier and anti-tumor therapy. The main contents are as follows:1.PDIs for specific molecule detection was first studied. We developed a fluorescent malononitrile-modified perylenediimide (MAPDI), which can selectively and rapidly react with nucleophiles, such as amines, amino acids and some inorganic anions, along with changes of UV-vis absorption and fluorescence emission. Detection limits of MAPDI for different nucleophiles were calculated to compare their strength of nucleophilicity. Furthermore, we found that MAPDI could respond to reductive inorganic anions with a significant red-shift of absorption peak. These results suggested that MAPDI was a potential nucleophile probe in organocatalytic reactions, metal ion-catalyzed reactions, reactions of amines and other nucleophilic chemical reactions.2.A multi-functional PDI derivative for ion detection, bio-probe and gene carrier was then investigated. Dithioacetal-modified perylenediimide (DTPDI)was synthesized as a highly sensitive and selective fluorescent chemosensor for recyclable Hg2+ detection as well as an effective DNA carrier. The central PDI chromophore allowed the tracing of cellular uptake by fluorescence microscopy; dithioacetals enabled detection of Hg2+; peripheral amine hydrochloride salts increased water solubility of DTPDI and also provided positive charges for noncovalent binding with negatively charged DNA. As a recyclable fluorescent probe for cellular Hg2+ detection, DTPDI can be rapidly internalized into live cells with low cytotoxicity and high DNA delivery efficacy.3.A multi-functional PDI derivative as anti-cancer agent and novel targeted drug carrier was also investigated. An amphiphilic anti-cancer prodrug RGD-PDI was obtained by firstly modifying PDI with zwitterionic group at imide position to obtain D-PDI, and secondly conjugating D-PDI with RGD peptide through a hydrolysable ester linkage. RGD-PDI preformed as a prodrug and released D-PDI was a DNA intercalator with anti-tumor effect. The self-assembly of RGD-PDI with hydrophobic drug camptothecin(CPT) was prepared in which RGD-PDI worked as a drug carrier. The assembly achieved dual release of D-PDI and CPT in cellular environment,which was effective in killing cancer cells and in suppressing cell resistance.Thus, RGD-PDI was an anti-cancer prodrug as well as a targeting drug carrier for tumor therapy.