Multifunctional biosensors based on peptide–polyelectrolyte conjugates. Issue 4 (8th January 2016)

• Record Type: Journal Article
• Authors: Kogikoski, S.; Sousa, C. P.; Liberato, M. S.; Andrade-Filho, T.; Prieto, T.; Ferreira, F. F.; Rocha, A. R.; Guha, S.; Alves, W. A.
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 4(2016)
• Page Start: 3223
• Page End: 3233
• Publication Date: 2016-01-08
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c5cp07165h
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The crystal structure of self-assembled peptide nanostructures dictates the conductivity. We show that the orthorhombic phase can be doped with PAH, improving hole and electron injection, opening opportunities for self-assembled peptide composites. Abstract : A novel enzymatic platform for the sensing of H2 O2 and glucose that usesl, 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 ( P 61 ) and orthorhombic ( P 221 21 ). 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.