Ordered nano-structure of a stamped self-organized protein layer on a HOPG surface using a HFB carrier

A groundbreaking method for ordered molecular layer preparation on a solid surface employing the drop-stamp method has been developed by us taking advantage of the characteristics of the HFB molecule as a self-organizer/adsorption carrier. It is a smart method which can be used to prepare a self-organized protein layer on a solid surface without unspecific adsorption or defects. In our previous report, we clarified the self-organizing nature of HFB-tagged protein molecules on a surface of a solution droplet. In this report, a protein layer was prepared on a HOPG surface by using the drop-stamp method with a maltose binding protein (MBP)-tagged HFBII molecule. The structure of the stamped protein layer was investigated using frequency modulation atomic force microscopy (FM-AFM) in a liquid condition. The FM-AFM images show that the drop-stamp method can prepare an ordered protein layer on a solid surface smartly. The drop-stamp method using a HFB carrier is a practical method which can be used to prepare an ordered protein layer on a solid substrate surface without unspecific adsorption defects.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Functional protein molecule (maltose binding protein, MBP) can be self-organized at air/water interface when it is genetically tagged with hydrophobin (HFBII) as molecular self-organizing carrier. ► MBP–HFBII forms self-organized mono-layer on a surface of the solution droplet. The MBP–HFBII layer can be stamped onto a solid material surface in self-organized form. ► If the MBP–HFBII fusion molecules and HFBII molecules are mixed in solution, MBP distribution can be controlled accurately on both the solution droplet surface and it stamped solid substrate surface.