title: Interactions between avidin and graphene for development of a biosensing platform.
abstract: Fundamental understanding of interactions at the interface of biological molecules, such as proteins, and nanomaterials is crucial for developing various biocompatible hybrid materials and biosensing platforms. Biosensors comprising of graphene-based conductive nanomaterials offer the advantage of higher sensitivity and reliable diagnosis mainly due to their superior specific surface area and ballistic conductivity. Furthermore, conductive nanocomposite structures that immobilize proteins can synergize the properties of both transducers and molecular recognition elements improving the performance of the biosensing device. Here we report for the first time, using a combined molecular dynamics simulations and experimental approach, the interactions between avidin and graphene for the development of a sensing platform that can be used for the detection of biological macromolecules such as mismatch repair proteins through biotinylated DNA substrates. We find that the interactive forces between avidin and graphene are mainly hydrophobic, along with some van der Waals, electrostatic and hydrogen bonding interactions. Notably, the structure and function of the avidin molecule are largely preserved after its adsorption on the graphene surface. The MD results agree well with scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS) analysis of avidin immobilized on a graphenated polypyrrole (G-PPy) conductive nanocomposite confirming the adsorption of avidin on graphene nanoplatelets as observed from the Fourier-transform infrared spectroscopy (FTIR).
authors.affiliation: Department of Computer Engineering, University of Bridgeport, Bridgeport, CT, 06604 USA; Department of Biomedical Engineering, University of Bridgeport, CT, 06604 USA. Electronic address: imacwan@bridgeport.edu.
authors.forename: Isaac
authors.initials: I
authors.lastname: Macwan
authors.affiliation: Department of Biomedical Engineering, University of Bridgeport, CT, 06604 USA. Electronic address: mdkhan@my.bridgeport.edu.
authors.forename: Md Daud Hossain
authors.initials: MDH
authors.lastname: Khan
authors.affiliation: Department of Biomedical Engineering, University of Bridgeport, CT, 06604 USA. Electronic address: aaphale@bridgeport.edu.
authors.forename: Ashish
authors.initials: A
authors.lastname: Aphale
authors.affiliation: Department of Biomedical Engineering, University of Bridgeport, CT, 06604 USA. Electronic address: shrsingh@my.bridgeport.edu.
authors.forename: Shrishti
authors.initials: S
authors.lastname: Singh
authors.affiliation: Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT, 06459 USA. Electronic address: jliu03@wesleyan.edu.
authors.forename: Juan
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT, 06459 USA. Electronic address: mhingorani@wesleyan.edu.
authors.forename: Manju
authors.initials: M
authors.lastname: Hingorani
authors.affiliation: Department of Biomedical Engineering, University of Bridgeport, CT, 06604 USA; Department of Mechanical Engineering, University of Bridgeport, Bridgeport, CT, 06604 USA. Electronic address: ppatra@bridgeport.edu.
authors.forename: Prabir
authors.initials: P
authors.lastname: Patra
mesh_terms: D000818:Animals; D001360:Avidin / Q000737:chemistry / Q000378:metabolism*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002645:Chickens / Q000378:metabolism*; D058266:Dielectric Spectroscopy / Q000295:instrumentation / Q000379:methods; D006108:Graphite / Q000737:chemistry / Q000378:metabolism*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D011108:Polymers / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry; D055672:Static Electricity
chemical_list: D055767:Immobilized Proteins; D011108:Polymers; D011758:Pyrroles; D001360:Avidin; C067635:polypyrrole; D006108:Graphite
keywords: Avidin; Biosensors; Electrochemical impedance; Graphene; Molecular dynamics