Patterning protein conjugates into organized microarrays with diphenylalanine peptide nanotubes self-assembled on graphite and gold electrode

Controlling the arrangement and organization of self-assembled peptide nanostructures is a crucial step in developing Lab-on-a-Chip devices based on biomolecular assembly. Here, we report a simple approach to achieve the vertically aligned assembly of diphenylalanine (FF) peptide by casting stock solution of FF peptide on gold and graphite modified silicones. We show at the first time the formation of highly ordered interlaced arrays of vertical flower crystals and peptide nanotubes (PNTs) on thiolated gold and graphite. Furthermore, their chemical stability was investigated in PBS buffer after 3 h to gain insight into the stability of modified electrodes upon cycling. Interestingly, a highly ordered hierarchical morphology was obtained on the substrate surface. Hierarchical morphology resembles a square lattice, dendritic forest, and three-dimensional packed arrays. The results confirmed that PNTs not only preserves its chemical stability but transform into hierarchical arrays in PBS which is very beneficial for their applications in bioelectrochemical and nanoelectronics devices. As an example, the significantly enhanced arrangement of antibody CD3 was also demonstrated at the PNTs modified gold electrode compared to unordered modified electrodes. The simple and mild approach described here opens a new path for the fabrication of organized self-assembled peptide bionanostructure arrays allowing the fabrication of a variety of microarrays used in practical applications.