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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

A Nonenzymatic Biosensor Based on Gold Electrodes Modified with Peptide Self-Assemblies for Detecting Ammonia and Urea Oxidation

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Author(s):
Bianchi, Roberta C. [1] ; da Silva, Emerson Rodrigo [1] ; Dall'Antonia, Luiz H. [2] ; Ferreira, Fabio Furlan [1] ; Alves, Wendel Andrade [1]
Total Authors: 5
Affiliation:
[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210580 Santo Andre, SP - Brazil
[2] Univ Estadual Londrina, Ctr Ciencias Exatas, Dept Quim, BR-86057970 Londrina, PR - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Langmuir; v. 30, n. 38, p. 11464-11473, SEP 30 2014.
Web of Science Citations: 23
Abstract

We have developed a nonenzymatic biosensor for the detection of ammonia and urea oxidation based on the deposition of peptide microstructures onto thiolated gold electrodes. FF-MNSs/MCP/Au assemblies were obtained by modifying gold substrates with 4-mercaptopyridine (MCP), followed by coating with l,l-diphenylalanine micro/nanostructures (FF-MNSs) grown in the solid-vapor phase. Benzene rings and amide groups with peptide micro/nanostructures interact with synthetic NH4(+) receptors through cation-? and hydrogen bonding. AuOH clusters on the Au surface provided the catalytic sites. The application of a predetermined concentration of analytes at the peptide interfaces activated the catalytic sites. We observed a relationship between the stability of films and the crystal structure of peptides, and we organized the FF-MNSs into an orthorhombic symmetry that was the most suitable assembly for creation of our biosensors. At 0.1 mol L(-1) NaOH, these FF-MNSs/MCP/Au electrodes have electrocatalytic properties regarding ammonia and urea oxidation that are comparable to those of enzyme-based architectures. Under optimal conditions, the electrocatalytic response is proportional to the ammonia and urea concentration in the range 0.1-1.0 mmol L(-1). The sensitivity was calculated as 2.83 and 81.3 ?A mmol L(-1) cm(-2) for ammonia and urea, respectively, at +0.40 V (vs SCE). Our detection method is easy to follow, does not require a mediator or enzyme, and has strong potential for detecting urea via nonenzymatic routes (AU)

FAPESP's process: 08/10537-3 - Study of crystalline pharmaceuticals polymorphs by X-ray powder diffraction and the Rietveld method
Grantee:Fabio Furlan Ferreira
Support Opportunities: Research Grants - Young Investigators Grants
FAPESP's process: 13/12997-0 - Hierarchical self-organization of peptide amphiphiles: fundamental mechanisms and potential applications
Grantee:Wendel Andrade Alves
Support Opportunities: Regular Research Grants
FAPESP's process: 13/12674-6 - Structural investigations on model systems based on amphiphilic peptides
Grantee:Emerson Rodrigo da Silva
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 11/05374-0 - Compounds with peptide functionalized nanostructured direct immobilization of polyaniline to urease
Grantee:Roberta Martins da Costa Bianchi
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
FAPESP's process: 08/57805-2 - Institute of Bioanalytics
Grantee:Lauro Tatsuo Kubota
Support Opportunities: Research Projects - Thematic Grants