title: Protein immobilization on Ni(II) ion patterns prepared by microcontact printing and dip-pen nanolithography.
abstract: An indirect method of protein patterning by using Ni(II) ion templates for immobilization via a specific metal-protein interaction is described. A nitrilotriacetic acid (NTA)-terminated self-assembled monolayer (SAM) allows oriented binding of histidine-tagged proteins via complexation with late first-row transition metal ions, such as Ni(II). Patterns of nickel(II) ions were prepared on NTA SAM-functionalized glass slides by microcontact printing (microCP) and dip-pen nanolithography (DPN) to obtain micrometer and submicrometer scale patterns. Consecutive dipping of the slides in 6His-protein solutions resulted in the formation of protein patterns, as was subsequently proven by AFM and confocal fluorescence microscopy. This indirect method prevents denaturation of fragile biomolecules caused by direct printing or writing of proteins. Moreover, it yields well-defined patterned monolayers of proteins and, in principle, is indifferent for biomolecules with a high molecular weight. This approach also enabled us to characterize the transfer of Ni(II) ions on fundamental parameters of DPN, such as writing speeds and tip-surface contact times, while writing with the smallest possible ink "molecules" (i.e., metal ions).
authors.affiliation: University of Twente, 7500 AE Enschede, The Netherlands.
authors.forename: Chien-Ching
authors.initials: CC
authors.lastname: Wu
authors.forename: David N
authors.initials: DN
authors.lastname: Reinhoudt
authors.forename: Cees
authors.initials: C
authors.lastname: Otto
authors.forename: Aldrik H
authors.initials: AH
authors.lastname: Velders
authors.forename: Vinod
authors.initials: V
authors.lastname: Subramaniam
mesh_terms: D000818:Animals; D037421:Anthozoa; D049452:Green Fluorescent Proteins / Q000737:chemistry / Q000378:metabolism; D006639:Histidine / Q000378:metabolism; D055767:Immobilized Proteins / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008164:Luminescent Proteins / Q000737:chemistry / Q000378:metabolism; D008970:Molecular Weight; D036103:Nanotechnology / Q000379:methods*; D009532:Nickel / Q000737:chemistry*; D011327:Printing / Q000379:methods*; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D013997:Time Factors
chemical_list: D055767:Immobilized Proteins; D008164:Luminescent Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D006639:Histidine; D009532:Nickel