Bioactive Protein Nanoarrays on Nickel Oxide Surfaces Formed by Dip-Pen Nanolithography†
C.A.M. and M.A.R. acknowledge the National Sciences Foundation NSEC program and the Department of Defence MURI/DURINT program for support of this research. S.W.H. acknowledges KOSEF for support of a postdoctoral fellowship.
Graphical Abstract
Ink flowing from a pen: Direct-write dip-pen nanolithography of His-tagged proteins (ubiquitin and thioredoxin) has been used to generate biologically active protein nanoarrays with feature sizes as small as 80 nm on nickel oxide surfaces without the need for an applied electric field. The protein molecules in this system seem to diffuse from the Ni-coated atomic force microscopy (AFM) tips to the Ni-coated substrate (see diagram).