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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.)

Self-assembled gold nanoparticles and amphiphile peptides: a colorimetric probe for copper(ii) ion detection

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Pelin, Juliane N. B. D. [1, 2] ; Edwards-Gayle, Charlotte J. C. [2] ; Martinho, Herculano [1] ; Gerbelli, Barbara B. [1] ; Castelletto, Valeria [2] ; Hamley, Ian W. [2] ; Alves, Wendel A. [1]
Total Authors: 7
[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210580 Santo Andre, SP - Brazil
[2] Univ Reading, Dept Chem, Reading RG6 6AD, Berks - England
Total Affiliations: 2
Document type: Journal article
Source: DALTON TRANSACTIONS; v. 49, n. 45, p. 16226-16237, DEC 7 2020.
Web of Science Citations: 1

Morphological, spectroscopic and scattering studies of the self-assembly and aggregation process of hybrids containing gold nanoparticles (AuNPs) and the amyloid peptides {[}RF](4) and P{[}RF](4) (where R = arginine; F = phenylalanine; P = proline) in aqueous solution were performed. Two methodologies were tested for the AuNP nucleation, using sodium borohydride (NaBH4) or epigallocatechin gallate (EGCG) as a reducing agent. This led to remarkable distinct modes of assembly, AuNP decorated fibrils with NaBH4 reduction or isolated AuNPs with EGCG reduction. For both methodologies, the presence of spherical AuNPs was observed by plasmonic resonance bands in absorption spectra at similar to 520 nm. Zeta potential measurements confirmed stable systems, with a similar aggregation state. Circular dichroism spectra revealed an antiparallel beta-sheet conformation of the peptides. The transmission electron microscopy (TEM) images showed the coexistence of nanometer fibers and globular nanoparticles with 20 nm size. The small-angle X-ray scattering (SAXS) results show that the NaBH4 systems presented large cylindrical structures, while with increasing P{[}RF](4) content, a decrease in radius was observed. However, the EGCG-AuNPs were characterized by spherical particles, with a radius of 10-20 nm. Also, the colorimetric efficiency of the hybrids in the capture of Cu2+ ions in solution was monitored. Raman spectroscopy data confirmed the conformation/structure of self-assembled samples. Moreover, there are indications for a surface-enhanced Raman spectroscopy (SERS) effect for Cu2+ sites. The set of results indicates that these systems could act as a promising sensitive metal concentration probes. (AU)

FAPESP's process: 18/05888-3 - Biosensors based on amphiphilic peptides for detection and diagnosis of diseases
Grantee:Barbara Bianca Gerbelli
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 15/20446-9 - Study of auto-organization in solution of hierarchical structures of peptide in presence of metallic nanoparticles
Grantee:Juliane Nogueira Batista Dias Pelin
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
FAPESP's process: 18/12535-0 - Self-organization of hierarchical structures of peptide in solution in presence of metallic nanoparticles
Grantee:Juliane Nogueira Batista Dias Pelin
Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
FAPESP's process: 17/02317-2 - Interfaces in materials: electronic, magnetic, structural and transport properties
Grantee:Adalberto Fazzio
Support Opportunities: Research Projects - Thematic Grants