title: Comparative sessile drop and dip pen nanolithography investigation for various hydrophilic ink/surface systems.
abstract: We present a dip pen nanolithography study of various hydrophilic ink/surface systems with application in the field of biosensors and novel nano-materials. The inking process was investigated by studying a number of inks, such as Deoxyribonucleic acid (DNA), Bovine serum albumin (BSA), Streptavidin, 16-mercaptohexadecanoic acid (MHA) and a 20 nm nanosphere (NS) polystyrene solution onto a range of substrates, namely glass, silicon, gold and tetrahedral amorphous carbon (taC). In the majority of cases, this resulted in patterns with sub-100 nm line widths and dot diameters. Importantly, contact angle measurements in the microl range showed a decrease of contact angle with drop volume, interpreted as a line tension effect. The significance of this to the nanoscale wetting behaviour is discussed. The effect of dwell time and writing speed indicates that the inking process is not solely defined by surface diffusion but also influenced by the ink dissolution rate from the tip.
authors.affiliation: Nanotechnology and Integrated BioEngineering Center, University of Ulster, Jordanstown, Shore Road, Newtownabbey BT37 0QB, United Kingdom.
authors.forename: Pradeep K
authors.initials: PK
authors.lastname: Yadav
authors.forename: Patrick
authors.initials: P
authors.lastname: Lemoine
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007281:Ink; D008422:Materials Testing; D044085:Microfluidics / Q000379:methods*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010781:Photography / Q000379:methods*; D013499:Surface Properties
chemical_list: D001704:Biopolymers