title: Molecular adsorption on graphene.
abstract: Current studies addressing the engineering of charge carrier concentration and the electronic band gap in epitaxial graphene using molecular adsorbates are reviewed. The focus here is on interactions between the graphene surface and the adsorbed molecules, including small gas molecules (H(2)O, H(2), O(2), CO, NO(2), NO, and NH(3)), aromatic, and non-aromatic molecules (F4-TCNQ, PTCDA, TPA, Na-NH(2), An-CH(3), An-Br, Poly (ethylene imine) (PEI), and diazonium salts), and various biomolecules such as peptides, DNA fragments, and other derivatives. This is followed by a discussion on graphene-based gas sensor concepts. In reviewing the studies of the effects of molecular adsorption on graphene, it is evident that the strong manipulation of graphene's electronic structure, including p- and n-doping, is not only possible with molecular adsorbates, but that this approach appears to be superior compared to these exploiting edge effects, local defects, or strain. However, graphene-based gas sensors, albeit feasible because huge adsorbate-induced variations in the relative conductivity are possible, generally suffer from the lack of chemical selectivity.
authors.affiliation: Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, Theodore Jorgensen Hall, 855 North 16th Street, University of Nebraska, PO Box 880299, Lincoln, NE 68588-0299, USA.
authors.forename: Lingmei
authors.initials: L
authors.lastname: Kong
authors.forename: Axel
authors.initials: A
authors.lastname: Enders
authors.forename: Talat S
authors.initials: TS
authors.lastname: Rahman
authors.forename: Peter A
authors.initials: PA
authors.lastname: Dowben
mesh_terms: D000327:Adsorption; D001665:Binding Sites; D001704:Biopolymers / Q000032:analysis* / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D003217:Conductometry / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D005740:Gases / Q000032:analysis* / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D001704:Biopolymers; D005740:Gases; D006108:Graphite