Lingtao Yu

Cu nanocrystal growth on peptide nanotubes by biomineralization: Size control of Cu nanocrystals by tuning peptide conformation

With recent interest in seeking new biologically inspired device-fabrication methods in nanotechnology, a new biological approach was examined to fabricate Cu nanotubes by using sequenced histidine-rich peptide nanotubes as templates. The sequenced histidine-rich peptide molecules were assembled as nanotubes, and the biological recognition of the specific sequence toward Cu lead to efficient Cu coating on the nanotubes. Cu nanocrystals were uniformly coated on the histidine-incorporated nanotubes with high packing density. In addition, the diameter of Cu nanocrystal was controlled between 10 and 30 nm on the nanotube by controlling the conformation of histidine-rich peptide by means of pH changes. Those nanotubes showed significant change in electronic structure by varying the nanocrystal diameter; therefore, this system may be developed to a conductivity-tunable building block for microelectronics and biological sensors. This simple biomineralization method can be applied to fabricate various metallic and semiconductor nanotubes with peptides whose sequences are known to mineralize specific ions.

Incorporation of sequenced peptides on nanotubes for Pt coating: smart control of nucleation and morphology via activation of metal binding sites on amino acids

A new method to fabricate morphology-controlled Pt nanotubes has been demonstrated by using sequenced peptide-functionalized nanotubes as templates. The sequenced peptide, His-Pro-Gly-Ala-His, was immobilized on template nanotubes, and the biomolecular recognition efficiently anchored Pt ions to nucleate Pt nanocrystals on the nanotubes. The morphology of the Pt coating on the nanotubes was controlled by switching Pt nucleation sites among the amino acids as a function of pH. While monodisperse Pt nanocrystals of average diameter 12 nm were grown on the nanotube surfaces in pH 8 solutions. This method that mimics biomineralization in nature can be used to produce nanotubes with controlled electrical properties from semiconducting to metallic in a simple and economical procedure, and this type of tunability may enable the resulting nanotubes to be applicable as smart building blocks in nanometer-scaled electronic devices and chemical sensors.