Luminescent nanoparticles from tripeptide-CdS conjugate

Self-assembly of two synthetic tripeptides containing ω-amino acids and α-aminoisobutyric acid is used to fabricate luminescent nanoparticles by doping with CdS quantum dots. The X-ray crystallography reveals that both the peptides exhibit an unusual turn structure in the solid state where N-terminal γ-aminobutyric acids prefer to adopt a gauche-gauche conformation. In higher order assembly, these peptides form a continuous hydrogen-bonded four-member nanoporous architecture. From methanol solution, the peptides form polydisperse nanospheres. The field emission scanning electron micrographs (FE-SEM) show that the average size of the nanospheres is in the range of 25 to 30 nm. Moreover, these peptide nanospheres can be efficiently doped with CdS quantum dots and exhibit optoelectronic properties.