title: Multiple MoS2 Transistors for Sensing Molecule Interaction Kinetics.
abstract: Atomically layered transition metal dichalcogenides (TMDCs) exhibit a significant potential to enable next-generation low-cost transistor biosensors that permit single-molecule-level quantification of biomolecules. To realize such potential biosensing capability, device-oriented research is needed for calibrating the sensor responses to enable the quantification of the affinities/kinetics of biomolecule interactions. In this work, we demonstrated MoS2-based transistor biosensors capable of detecting tumor necrosis factor--alpha (TNF-α) with a detection limit as low as 60 fM. Such a detection limit was achieved in both linear and subthreshold regimes of MoS2 transistors. In both regimes, all sets of transistors exhibited consistent calibrated responses with respect to TNF-α concentration, and they resulted in a standard curve, from which the equilibrium constant of the antibody-(TNF-α) pair was extracted to be KD = 369 ± 48 fM. Based on this calibrated sensor model, the time-dependent binding kinetics was also measured and the association/dissociation rates of the antibody-(TNF-α) pair were extracted to be (5.03 ± 0.16) × 10(8) M(-1) s(-1) and (1.97 ± 0.08) × 10(-4) s(-1), respectively. This work advanced the critical device physics for leveraging the excellent electronic/structural properties of TMDCs in biosensing applications as well as the research capability in analyzing the biomolecule interactions with fM-level sensitivities.
authors.affiliation: Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109.
authors.forename: Hongsuk
authors.initials: H
authors.lastname: Nam
authors.affiliation: Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109.
authors.forename: Bo-Ram
authors.initials: BR
authors.lastname: Oh
authors.affiliation: Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109.
authors.forename: Pengyu
authors.initials: P
authors.lastname: Chen
authors.affiliation: Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109.
authors.forename: Mikai
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109.
authors.forename: Sungjin
authors.initials: S
authors.lastname: Wi
authors.affiliation: University of Michigan-Shanghai Jiao Tong University Joint Institute and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Wan
authors.affiliation: Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109.
authors.forename: Katsuo
authors.initials: K
authors.lastname: Kurabayashi
authors.affiliation: Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109.
authors.forename: Xiaogan
authors.initials: X
authors.lastname: Liang
mesh_terms: D000906:Antibodies / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004220:Disulfides / Q000737:chemistry*; D004867:Equipment Design; D007700:Kinetics; D057230:Limit of Detection; D008982:Molybdenum / Q000737:chemistry*; D014173:Transistors, Electronic; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis* / Q000276:immunology
chemical_list: D000906:Antibodies; D004220:Disulfides; D014409:Tumor Necrosis Factor-alpha; D008982:Molybdenum; C082964:molybdenum disulfide