Study On Fluorescent Nanoparticles Co-assembled By Short Peptides And Catecholamines

The gradual deepening of researchers' exploration of life,a variety of life phenomena have been discovered,and the inspiration from life continues to emerge.At present,the popular molecular assembly comes from the inspiration of life,and the behavior of molecular assembly widely exists in the life system,such as the exchange between cell membranes,during exocytosis and folding of most spherical proteins in the process of translation.Nowadays,molecular assembly has become a development platform to explore new multi-functional materials,in which the synthesis of fluorescent materials is no longer limited to chemical synthesis,molecular assembly is also gradually involved in it.The structure of catecholamines is very similar to tyrosine in aromatic amino acids,we speculate that they have properties similar to aromatic amino acids,which has attracted our attention.In the selection of short peptides,we have found that after self-assembly,the natural GHK-Cu2+ complexes in human blood not only greatly improve their ability to be similar to growth factors,but also produce weak blue fluorescence.The results suggest that short peptides composed of non-aromatic amino acids can also be self-assembled to form fluorescent nanomaterials,which is inspired by this result.By combining short peptides with small catecholamines,we developed a new method to design fluorescent nanosensors by co-assembly of two kinds of biomolecules.By making full use of the accumulation of ?-? between carbon rings and the oxidizability of dopamine(DA),an important neurotransmitter of catecholamines,we successfully assembled oxidized DA(DAox)with aminated tripeptide H-GHK-NH2 after proper pH regulation,and successfully constructed an ultra-sensitive and stable fluorescent pH nanosensor.In this study,the quantum yield of H-GHK-NH2+DAox nanomaterials synthesized under pH8 conditions is 20.44%,and the particle size is 349±20 nm.It is stable and has extremely regular linear response in the range of pH3-9,which may be one of the brightest fluorescent nanostructures co-assembled only by biomolecules.We can foresee that this method can not only open up a new way for the construction of hybrid nanostructures,but also provide clues for the production of bioluminescence in vivo.