title: Multifunctional biosensors based on peptide-polyelectrolyte conjugates.
abstract: A novel enzymatic platform for the sensing of H2O2 and glucose that uses L,L-diphenylalanine micro/nanostructures (FF-MNSs) as an enzyme support is shown. This platform is obtained by the self-assembly of poly(allylamine hydrochloride) (PAH), FF-MNSs, and microperoxidase-11 (MP11) anchored onto the peptide matrix, in two different crystal structures of FF-MNSs: hexagonal (P61) and orthorhombic (P22121). The electroactive area of the electrodes increases in the presence of FF-MNSs. We also demonstrate via theoretical calculations that the valence band energy of the orthorhombic structure allows it to be doped, similarly to p-type semiconductors, where PAH acts as a doping agent for the orthorhombic peptide structure, decreasing the band-gap by around 1 eV, which results in a smaller charge transfer resistance. These results are consistent with electrochemical impedance spectroscopy measurements, which further elucidate the role of the band structure of the orthorhombic FF-MNSs in the conductivity and electron transfer rates of the hybrid material. An effective communication between the electrode and the active site of a glucose oxidase enzyme through MP11-protein complexes occurs, paving the way for FF-MNSs in the orthorhombic phase for the future development of bioelectronics sensing devices.
authors.affiliation: Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-580, Santo André, SP, Brazil. wendel.alves@ufabc.edu.br.
authors.forename: S
authors.initials: S
authors.lastname: Kogikoski
authors.affiliation: Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-580, Santo André, SP, Brazil. wendel.alves@ufabc.edu.br.
authors.forename: C P
authors.initials: CP
authors.lastname: Sousa
authors.affiliation: Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-580, Santo André, SP, Brazil. wendel.alves@ufabc.edu.br.
authors.forename: M S
authors.initials: MS
authors.lastname: Liberato
authors.affiliation: Instituto de Ciências Exatas, Faculdade de Física, Universidade Federal do Sul e Sudeste do Pará, Campus Marabá, 68505-080, Marabá, Pará, Brazil.
authors.forename: T
authors.initials: T
authors.lastname: Andrade-Filho
authors.affiliation: Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-580, Santo André, SP, Brazil. wendel.alves@ufabc.edu.br.
authors.forename: T
authors.initials: T
authors.lastname: Prieto
authors.affiliation: Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-580, Santo André, SP, Brazil. wendel.alves@ufabc.edu.br.
authors.forename: F F
authors.initials: FF
authors.lastname: Ferreira
authors.affiliation: Instituto de Física Teórica, Universidade Estadual Paulista - UNESP, São Paulo, SP, Brazil.
authors.forename: A R
authors.initials: AR
authors.lastname: Rocha
authors.affiliation: Department of Physics of Astronomy, University of Missouri, Columbia, Missouri 65211, USA.
authors.forename: S
authors.initials: S
authors.lastname: Guha
authors.affiliation: Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-580, Santo André, SP, Brazil. wendel.alves@ufabc.edu.br.
authors.forename: W A
authors.initials: WA
authors.lastname: Alves
mesh_terms: D015374:Biosensing Techniques; D004573:Electrolytes / Q000737:chemistry*; D005947:Glucose / Q000032:analysis; D006861:Hydrogen Peroxide / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: D004573:Electrolytes; D010455:Peptides; D006861:Hydrogen Peroxide; D005947:Glucose