| Short peptides have great potential applications in biosensing, drug delivery, tissue engineering and optoelectronic materials due to the advantages of low-molecular-weight, facile synthesis and purification, well chemical versatility and good biocompatibility. Researchers have devoted themselves to modified appropriate groups, e.g., electrochemical, photochemical moitiesonto short peptides, thus combining the well designed functions and good self-assembled abilities to obtain supramolecular materials with the corresponding functions.Based on the above considerations, the study here focused on the functionalized short peptides, from design, synthesis to self-assembled nanomaterials and their applications in many fields (e.g. biosensors, nanofabrications, drug delivery, catalysis and so on). The results are as follows:(1) The conjugates of ferrocene and Phe-Phe (FF) dipeptide, Fc-FF-OMe and Fc-FF-OH were synthesized by HOBt/HBTU protocol in solution. Using various strategies, the derivatives can self-assmeble into nanowires, nanofibers, nanospheres and vertical aligned nanowires. Self-assembled Fc-FF-OMe nanowire, Fc-PNW, was designed for the fabrication of electrochemical immunosensor to detect TNF-α. The large specific surface area of Fc-PNW could increase the loading of Ab1, while the Fc moiety on the PNW can be used as anelectron mediator for Ab2label, GOx. The resulting immunosensor has high sensitivity, wide linear range (0.005-10ng/mL) and good selectivity. In addition, nanowires and nanofibers can be a template for preparation of magnetic nanoparticles aftersintering process.(2) The gelator ferrocene-phenylalanine (Fc-F) was synthesized by HOBt/HBTU protocol in solution. Fc-F can self-assemble into supramolecular hydrogel at physiological pH and room temperature. The hydrogel was responsed to multiple-stimuli (e.g., heat, pH, shear force and redox stimulus). Fc-F and carbon nanotubes can co-assemble into a hybrid gel and it can be used as platform forthe fabrication of biosensor. In addition, the porous structure of the gel can load drug molecules and expands its application in drug delivery.(3) Using self-assembled strategy, nanospheres and supramolecular hydrogels were prepared based on commercially available Fmoc-amino acids. The morphology of the nanospheres is relatively homogeneous and the size can be finely tuned by adjusting concentration of the Fmoc-amino acids. The hydrogels can be simply prepared by ultrasound and their morphology were generally nanofibrils with diameter about30～70nm. Both Nanospheres and hydrogels are based on cheap, easily and commercially available amino acids. They show good stability at physiological pH and room temperature. In addition, the preparation method is simple and fast. All these advantages pave the way for the industrial application of amino acids based nanospheres and hydrogels. |
