Univ Fed Sul & Sudeste Para, Fac Fis, Inst Ciencias Exatas, Campus Maraba, BR-68505080 Maraba, Para - Brazil
 Univ Estadual Paulista UNESP, Inst Fis Teor, Sao Paulo, SP - Brazil
 Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 - USA
Total Affiliations: 4
Physical Chemistry Chemical Physics;
JAN 28 2016.
Web of Science Citations:
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 (P6(1)) and orthorhombic (P22(1)2(1)). 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. (AU)