title: Electrical Probing and Tuning of Molecular Physisorption on Graphene.
abstract: The ability to tune the molecular interaction electronically can have profound impact on wide-ranging scientific frontiers in catalysis, chemical and biological sensor development, and the understanding of key biological processes. Despite that electrochemistry is routinely used to probe redox reactions involving loss or gain of electrons, electrical probing and tuning of the weaker noncovalent interactions, such as molecular physisorption, have been challenging, primarily due to the inability to change the work function of conventional metal electrodes. To this end, we report electrical probing and tuning of the noncovalent physisorption of polar molecules on graphene surface by using graphene nanoelectronic heterodyne sensors. Temperature-dependent molecular desorptions for six different polar molecules were measured in real-time to study the desorption kinetics and extract the binding affinities. More importantly, we demonstrate electrical tuning of molecule-graphene binding kinetics through electrostatic gating of graphene; the molecular desorption can be slowed down nearly three times within a gate voltage range of 15 V. Our results provide insight into small molecule-nanomaterial interaction dynamics and signify the ability to electrically tailor interactions, which can lead to rational designs of complex chemical processes for catalysis and drug discovery.
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan , 1301 Beal Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: Girish S
authors.initials: GS
authors.lastname: Kulkarni
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan , 1301 Beal Avenue, Ann Arbor, Michigan 48109, United States.|Department of Biomedical Engineering, University of Michigan , 1101 Beal Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: Karthik
authors.initials: K
authors.lastname: Reddy
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan , 1301 Beal Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: Wenzhe
authors.initials: W
authors.lastname: Zang
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan , 1301 Beal Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: Kyunghoon
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of Biomedical Engineering, University of Michigan , 1101 Beal Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: Xudong
authors.initials: X
authors.lastname: Fan
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan , 1301 Beal Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Zhong
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D002384:Catalysis; D004563:Electrochemistry; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D013696:Temperature
chemical_list: D008670:Metals; D006108:Graphite
keywords: Noncovalent interaction; binding energy; electrical tuning; graphene; heterodyne sensor; physisorption