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de Sousa RR, Heinze DA, Sacramento JB, Lanfredi AJC, Carastan DJ. Electrical Conductivity and In Situ SAXS Probing of Block Copolymer Nanocomposites Under Mechanical Stretching. ACS Appl Mater Interfaces 2023. [PMID: 37235644 DOI: 10.1021/acsami.3c03573] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Elastomers based on block copolymers can self-organize into ordered nanoscale structures, making them attractive for use as flexible conductive nanocomposites. Understanding how ordered structures impact electrical properties is essential for practical applications. This study investigated the morphological evolution of flexible conductive elastomers based on polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) block copolymers with aligned single- or multi-wall carbon nanotubes (SWCNTs or MWCNTs) and their electrical conductivity under large deformations. Oriented nanocomposites were obtained through injection molding and characterized using two different setups: tensile testing monitored by in situ small-angle X-ray scattering (SAXS) and tensile testing with simultaneous electrical conductivity measurements. Our findings demonstrate that structural orientation significantly influences electrical conductivity, with higher conductivity in the longitudinal direction due to the preferred orientation of carbon nanotubes. Tensile testing demonstrated that carbon nanotubes accelerate the process of realignment of the ordered structure. As a consequence, higher deformations reduced the conductivity of samples with longitudinal alignment due to the disruption of percolation contacts between nanotubes, while in samples with a transverse alignment the process promoted the formation of a new conductive network, increasing electrical conductivity.
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Affiliation(s)
- Rogerio R de Sousa
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC (UFABC), Av. Dos Estados, 5001, Santo André, São Paulo 09210-580, Brazil
| | - Daniel A Heinze
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC (UFABC), Av. Dos Estados, 5001, Santo André, São Paulo 09210-580, Brazil
| | - Joana B Sacramento
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC (UFABC), Av. Dos Estados, 5001, Santo André, São Paulo 09210-580, Brazil
| | - Alexandre J C Lanfredi
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC (UFABC), Av. Dos Estados, 5001, Santo André, São Paulo 09210-580, Brazil
| | - Danilo J Carastan
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC (UFABC), Av. Dos Estados, 5001, Santo André, São Paulo 09210-580, Brazil
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2
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Nunez FA, Castro ACH, Daher IP, Cunha-Neto E, Kalil J, Boscardin SB, Lanfredi AJC, de Oliveira VL, Alves WA. ZnO-Based Electrochemical Immunosensor to Assess Vaccine-Induced Antibody-Mediated Immunity against Wild-Type and Gamma SARS-CoV-2 Strains. Biosensors (Basel) 2023; 13:371. [PMID: 36979583 PMCID: PMC10046366 DOI: 10.3390/bios13030371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/05/2023] [Accepted: 03/09/2023] [Indexed: 06/18/2023]
Abstract
The evaluation of serological responses to COVID-19 is crucial for population-level surveillance, developing new vaccines, and evaluating the efficacy of different immunization programs. Research and development of point-of-care test technologies remain essential to improving immunity assessment, especially for SARS-CoV-2 variants that partially evade vaccine-induced immune responses. In this work, an impedimetric biosensor based on the immobilization of the recombinant trimeric wild-type spike protein (S protein) on zinc oxide nanorods (ZnONRs) was employed for serological evaluation. We successfully assessed its applicability using serum samples from spike-based COVID-19 vaccines: ChAdOx1-S (Oxford-AstraZeneca) and BNT162b2 (Pfizer-BioNTech). Overall, the ZnONRs/ spike-modified electrode displayed accurate results for both vaccines, showing excellent potential as a tool for assessing and monitoring seroprevalence in the population. A refined outcome of this technology was achieved when the ZnO immunosensor was functionalized with the S protein from the P.1 linage (Gamma variant). Serological responses against samples from vaccinated individuals were acquired with excellent performance. Following studies based on traditional serological tests, the ZnONRs/spike immunosensor data reveal that ChAdOx1-S vaccinated individuals present significantly less antibody-mediated immunity against the Gamma variant than the BNT162b2 vaccine, highlighting the great potential of this point-of-care technology for evaluating vaccine-induced humoral immunity against different SARS-CoV-2 strains.
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Affiliation(s)
- Freddy A. Nunez
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, São Paulo 09210-580, Brazil
| | - Ana C. H. Castro
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, São Paulo 09210-580, Brazil
| | - Isabela P. Daher
- Laboratorio de Imunologia, INCOR, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, São Paulo 05403-900, Brazil
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, São Paulo 05508-900, Brazil
| | - Edecio Cunha-Neto
- Laboratorio de Imunologia, INCOR, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, São Paulo 05403-900, Brazil
- LIM-19, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, São Paulo 05403-900, Brazil
| | - Jorge Kalil
- Laboratorio de Imunologia, INCOR, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, São Paulo 05403-900, Brazil
- LIM-19, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, São Paulo 05403-900, Brazil
| | - Silvia B. Boscardin
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, São Paulo 05508-900, Brazil
| | - Alexandre J. C. Lanfredi
- Centro de Engenharia, Modelagem e Ciências Sociais Aplicadas, Universidade Federal do ABC, São Paulo 09210-580, Brazil
| | - Vivian L. de Oliveira
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, São Paulo 09210-580, Brazil
- Laboratorio de Imunologia, INCOR, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, São Paulo 05403-900, Brazil
- LIM-19, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, São Paulo 05403-900, Brazil
| | - Wendel A. Alves
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, São Paulo 09210-580, Brazil
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3
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Nunez FA, Castro ACH, de Oliveira VL, Lima AC, Oliveira JR, de Medeiros GX, Sasahara GL, Santos KS, Lanfredi AJC, Alves WA. Electrochemical Immunosensors Based on Zinc Oxide Nanorods for Detection of Antibodies Against SARS-CoV-2 Spike Protein in Convalescent and Vaccinated Individuals. ACS Biomater Sci Eng 2023; 9:458-473. [PMID: 36048716 PMCID: PMC9469957 DOI: 10.1021/acsbiomaterials.2c00509] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/24/2022] [Indexed: 01/11/2023]
Abstract
Even after over 2 years of the COVID-19 pandemic, research on rapid, inexpensive, and accurate tests remains essential for controlling and avoiding the global spread of SARS-CoV-2 across the planet during a potential reappearance in future global waves or regional outbreaks. Assessment of serological responses for COVID-19 can be beneficial for population-level surveillance purposes, supporting the development of novel vaccines and evaluating the efficacy of different immunization programs. This can be especially relevant for broadly used inactivated whole virus vaccines, such as CoronaVac, which produced lower titers of neutralizing antibodies. and showed lower efficacy for specific groups such as the elderly and immunocompromised. We developed an impedimetric biosensor based on the immobilization of SARS-CoV-2 recombinant trimeric spike protein (S protein) on zinc oxide nanorod (ZnONR)-modified fluorine-doped tin oxide substrates for COVID-19 serology testing. Due to electrostatic interactions, the negatively charged S protein was immobilized via physical adsorption. The electrochemical response of the immunosensor was measured at each modification step and characterized by scanning electron microscopy and electrochemical techniques. We successfully evaluated the applicability of the modified ZnONR electrodes using serum samples from COVID-19 convalescent individuals, CoronaVac-vaccinated with or without positive results for SARS-CoV-2 infection, and pre-pandemic samples from healthy volunteers as controls. ELISA for IgG anti-SARS-CoV-2 spike protein was performed for comparison, and ELISA for IgG anti-RBDs of seasonal coronavirus (HCoVs) was used to test the specificity of immunosensor detection. No cross-reactivity with HCoVs was detected using the ZnONR immunosensor, and more interestingly, the sensor presented higher sensitivity when compared to negative ELISA results. The results demonstrate that the ZnONRs/spike-modified electrode displayed sensitive results for convalescents and vaccinated samples and shows excellent potential as a tool for the population's assessment and monitoring of seroconversion and seroprevalence.
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Affiliation(s)
- Freddy A. Nunez
- Centro de Ciências Naturais e Humanas,
Universidade Federal do ABC, Av. dos Estados, 5001, Santo
André, São Paulo09210-580, Brazil
| | - Ana C. H. Castro
- Centro de Ciências Naturais e Humanas,
Universidade Federal do ABC, Av. dos Estados, 5001, Santo
André, São Paulo09210-580, Brazil
| | - Vivian L. de Oliveira
- Centro de Ciências Naturais e Humanas,
Universidade Federal do ABC, Av. dos Estados, 5001, Santo
André, São Paulo09210-580, Brazil
- Laboratório de Imunologia, LIM19, Instituto do
Coração (InCor), Hospital das Clínicas da Faculdade de
Medicina da Universidade de São Paulo (HCFMUSP), Av. Dr. Arnaldo,
44, São Paulo, São Paulo05403-900, Brazil
| | - Ariane C. Lima
- Departamento de Clínica Médica, Disciplina
de Alergia e Imunologia Clínica, Faculdade de Medicina da Universidade
de São Paulo, Av. Dr. Arnaldo, 455, São Paulo, São
Paulo01246-903, Brazil
| | - Jamille R. Oliveira
- Departamento de Clínica Médica, Disciplina
de Alergia e Imunologia Clínica, Faculdade de Medicina da Universidade
de São Paulo, Av. Dr. Arnaldo, 455, São Paulo, São
Paulo01246-903, Brazil
| | - Giuliana X. de Medeiros
- Departamento de Clínica Médica, Disciplina
de Alergia e Imunologia Clínica, Faculdade de Medicina da Universidade
de São Paulo, Av. Dr. Arnaldo, 455, São Paulo, São
Paulo01246-903, Brazil
| | - Greyce L. Sasahara
- Laboratório de Imunologia, LIM19, Instituto do
Coração (InCor), Hospital das Clínicas da Faculdade de
Medicina da Universidade de São Paulo (HCFMUSP), Av. Dr. Arnaldo,
44, São Paulo, São Paulo05403-900, Brazil
| | - Keity S. Santos
- Laboratório de Imunologia, LIM19, Instituto do
Coração (InCor), Hospital das Clínicas da Faculdade de
Medicina da Universidade de São Paulo (HCFMUSP), Av. Dr. Arnaldo,
44, São Paulo, São Paulo05403-900, Brazil
- Departamento de Clínica Médica, Disciplina
de Alergia e Imunologia Clínica, Faculdade de Medicina da Universidade
de São Paulo, Av. Dr. Arnaldo, 455, São Paulo, São
Paulo01246-903, Brazil
| | - Alexandre J. C. Lanfredi
- Centro de Engenharia, Modelagem e Ciências
Sociais Aplicadas, Universidade Federal do ABC, Av. dos
Estados, 5001, Santo André, São Paulo09210-580,
Brazil
| | - Wendel A. Alves
- Centro de Ciências Naturais e Humanas,
Universidade Federal do ABC, Av. dos Estados, 5001, Santo
André, São Paulo09210-580, Brazil
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4
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Sobrinho LF, Nascimento OR, Icimoto MY, Lanfredi AJC, Droppa R, Nantes IL. Oligomerization of photochemically oxidized phenothiazine by nanostructured
α‐Fe
2
O
3
. POLYM INT 2022. [DOI: 10.1002/pi.6496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Luiza F. Sobrinho
- Universidade Federal do ABC, Avenida dos Estados 5001 Santo André SP Brazil
| | - Otaciro R. Nascimento
- Universidade de São Paulo, Instituto de Física de São Carlos, Campus II, Avenida João Dagnone, n° 1100, Jardim Santa Angelina ‐ CEP 13563‐120 São Carlos SP Brazil
| | - Marcelo Y. Icimoto
- Universidade Federal de São Paulo, Rua 3 de Maio, 100 São Paulo SP Brazil
| | | | - Roosevelt Droppa
- Universidade Federal do ABC, Avenida dos Estados 5001 Santo André SP Brazil
| | - Iseli L. Nantes
- Universidade Federal do ABC, Avenida dos Estados 5001 Santo André SP Brazil
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5
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Belleti E, Bevilaqua VR, Brito AMM, Modesto DA, Lanfredi AJC, Viviani VR, Nantes-Cardoso IL. Synthesis of bioluminescent gold nanoparticle-luciferase hybrid systems for technological applications. Photochem Photobiol Sci 2021; 20:1439-1453. [PMID: 34613602 PMCID: PMC8493054 DOI: 10.1007/s43630-021-00111-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/27/2021] [Indexed: 11/01/2022]
Abstract
Bioluminescent gold nanoparticles (AuNPs) were synthesized in situ using dithiol-terminated polyethylene glycol (PEG(SH)2) as reducer and stabilizing agents. Hybrid Au/F3O4 nanoparticles were also produced in a variation of synthesis, and both types of nanostructures had the polymer capping replaced by L-cysteine (Cys). The four types of nanoparticles, PEG(SH)2AuNPs, PEG(SH)2Au/F3O4NPs, CysAuNPs, and CysAu/F3O4NPs were associated with purified recombinant Pyrearinus termitilluminans green emitting click beetle luciferase (PyLuc) and Phrixotrix hirtus (RELuc) red-emitting railroad worm luciferase. Enzyme association with PEG(SH)2 was also investigated as a control. Luciferases were chosen because they catalyze bioluminescent reactions used in a wide range of bioanalytical applications, including ATP assays, gene reporting, high-throughput screening, bioluminescence imaging, biosensors and other bioluminescence-based assays. The immobilization of PyLuc and RELuc promoted partial suppression of the enzyme luminescence activity in a functionalization-dependent way. Association of PyLuc and RELuc with AuNPs increased the enzyme operational stability in relation to the free enzyme, as evidenced by the luminescence intensity from 0 to 7 h after substrate addition. The stability of the immobilized enzymes was also functionalization-dependent and the association with CysAuNPs was the condition that combined more sustained luminescent activity with a low degree of luminescence quenching. The higher enzymatic stability and sustained luminescence of luciferases associated with nanoparticles may improve the applicability of bioluminescence for bioimaging and biosensing purposes.
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Affiliation(s)
- Elisângela Belleti
- Universidade Federal do ABC (UFABC), Av. dos Estados, 5001, Bairro Bangu, Santo André, SP, 09210-580, Brazil
| | - Vanessa R Bevilaqua
- Graduate School of Evolutive Genetics and Molecular Biology (UFSCar), São Carlos, SP, Brazil
| | - Adrianne M M Brito
- Universidade Federal do ABC (UFABC), Av. dos Estados, 5001, Bairro Bangu, Santo André, SP, 09210-580, Brazil
| | - Diego A Modesto
- Universidade Federal do ABC (UFABC), Av. dos Estados, 5001, Bairro Bangu, Santo André, SP, 09210-580, Brazil
| | - Alexandre J C Lanfredi
- Universidade Federal do ABC (UFABC), Av. dos Estados, 5001, Bairro Bangu, Santo André, SP, 09210-580, Brazil
| | - Vadim R Viviani
- Universidade Federal do ABC (UFABC), Av. dos Estados, 5001, Bairro Bangu, Santo André, SP, 09210-580, Brazil
- Graduate School of Biotechnology and Environmental Monitoring (UFSCar), Sorocaba, SP, Brazil
| | - Iseli L Nantes-Cardoso
- Universidade Federal do ABC (UFABC), Av. dos Estados, 5001, Bairro Bangu, Santo André, SP, 09210-580, Brazil.
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6
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Medina MS, Ramirez BN, Ferreira PMGL, Huang HP, Zenatti A, Lanfredi AJC, Escote MT. Low oxygen pressure synthesis of NdNiO3-δ nanowires by electrospinning. Nano Ex 2020. [DOI: 10.1088/2632-959x/ab8a77] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
Synthesis of RNiO3 (R = rare earth) nanowires can be interesting as building blocks with potential applications in optoelectronic devices. Here, we describe the synthesis and characterization of NdNiO3-δ
(NNO) nanowires produced by electrospinning technique via polymeric precursor solution at relatively low temperature and oxygen pressure. These NNO nanowires were characterized by x-ray diffraction (XRD), x-ray photodetection spectroscopy (XPS), Field Emission Scanning Electron Microscopy (Fe-SEM), Magnetization (M(T)) and electrical resistance (R(T)) measurements. SEM images revealed a granular nanowire microstructure of NNO nanostructures, with a distribution of nanowire diameters ranging from 50 to 150 nm. The NNO nanowires also exhibit granular characteristics with an average grain diameter of 40 nm. The x-ray diffraction patterns of the NNO nanowires indicated that these samples exhibited a high degree of crystallinity and their Bragg reflections can be indexed to an orthorhombic-distorted (Pbnm symmetry) perovskite structure. The crystalline structure seems to be slightly texturized in some Bragg directions and with a slightly strained crystallite. M(T) and R(T) measurement as a function of temperature curves show that these NNO samples present a metal-insulator (MI) transition close to T
MI
∼ 198 K, which is usually observed in NNO thin films and bulk samples. The nanostructured shape and these experimental observations can be promising in designing new electronic devices using this strongly correlated oxide.
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7
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Batista AM, de Queiroz TB, Antunes RA, Lanfredi AJC, Benvenho ARV, Bonvent JJ, Martinho H. Gold nanochannels oxidation by confined water. RSC Adv 2020; 10:36980-36987. [PMID: 35521283 PMCID: PMC9057077 DOI: 10.1039/d0ra05830k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 09/09/2020] [Indexed: 12/03/2022] Open
Abstract
Confined and interstitial water has a key role in several chemical, physical and biological processes. It is remarkable that many aspects of water behavior in this regime (e.g., chemical reactivity) remain obscure and unaddressed. In particular for gold surfaces, results from simulations indicated that the first wetting layer would present hydrophilic behavior in contrast to the overall hydrophobic character of the bulk water on this surface. In the present work we investigate the properties of confined water on Au 〈111〉 nanochannels. Our findings, based on a large set of morphological, structural and spectroscopic experimental data and ab initio computer simulations, strongly support the hypothesis of hydrophilicity of the first wetting layer of the Au 〈111〉 surface. A unique oxidation process was also observed in the nanochannels driven by confined water. Our findings indicated that the oxidation product is Au(OH)3. Therefore, the Au surface reactivity against confined water needs to be considered for nanoscopic applications such as, e.g., catalysis in fine chemicals, pharmaceuticals, and the food industry green processes. We investigate the properties of confined water on Au 〈111〉 nanochannels. We report an unique oxidation process was also observed in the nanochannels driven by first wetting layer of the surface.![]()
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8
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Tofanello A, Miranda ÉA, Dias IWR, Lanfredi AJC, Arantes JT, Juliano M, Nantes IL. pH-Dependent Synthesis of Anisotropic Gold Nanostructures by Bioinspired Cysteine-Containing Peptides. ACS Omega 2016; 1:424-434. [PMID: 31457138 PMCID: PMC6640750 DOI: 10.1021/acsomega.6b00140] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 09/06/2016] [Indexed: 05/28/2023]
Abstract
In the present study, alkaline peptides AAAXCX (X = lysine or arginine residues) were designed based on the conserved motif of the enzyme thioredoxin and used for the synthesis of gold nanoparticles (GNPs) in the pH range of 2-11. These peptides were compared with free cysteine, the counterpart acidic peptides AAAECE and γ-ECG (glutathione), and the neutral peptide AAAACA. The objective was to investigate the effect of the amino acids neighboring a cysteine residue on the pH-dependent synthesis of gold nanocrystals. Kohn-Sham density functional theory (KS-DFT) calculations indicated an increase in the reducing capacity of AAAKCK favored by the successive deprotonation of their ionizable groups at increasing pH values. Experimentally, it was observed that gold speciation and the peptide structure also have a strong influence on the synthesis and stabilization of GNPs. AAAKCK produced GNPs at room temperature, in the whole investigated pH range. By contrast, alkaline pH was the best condition for the synthesis of GNP assisted by the AAARCR peptide. The acidic peptides produced GNPs only in the presence of polyethylene glycol, and the synthesis using AAAECE and γ-ECG also required heating. The ionization state of AAAKCK had a strong influence on the preferential growth of the GNPs. Therefore, pH had a remarkable effect on the synthesis, kinetics, size, shape, and polydispersity of GNPs produced using AAAKCK. The AAAKCK peptide produced anisotropic decahedral and platelike nanocrystals at acidic pH values and spherical GNPs at alkaline pH values. Both alkaline peptides were also efficient capping agents for GNPs, but they produced a significant difference in the zeta potential, probably because of different orientations on the gold surface.
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Affiliation(s)
- Aryane Tofanello
- NanoBioMAv, Centro de Ciências Naturais e Humanas (CCNH) and Centro de Engenharia,
Modelagem e Ciências Sociais Aplicadas (CECS), Universidade Federal do ABC (UFABC), Avenida dos Estados 5001, Bairro Bangu, 09210-580 Santo André, São Paulo, Brazil
| | - Érica
G. A. Miranda
- NanoBioMAv, Centro de Ciências Naturais e Humanas (CCNH) and Centro de Engenharia,
Modelagem e Ciências Sociais Aplicadas (CECS), Universidade Federal do ABC (UFABC), Avenida dos Estados 5001, Bairro Bangu, 09210-580 Santo André, São Paulo, Brazil
| | - Igor W. R. Dias
- NanoBioMAv, Centro de Ciências Naturais e Humanas (CCNH) and Centro de Engenharia,
Modelagem e Ciências Sociais Aplicadas (CECS), Universidade Federal do ABC (UFABC), Avenida dos Estados 5001, Bairro Bangu, 09210-580 Santo André, São Paulo, Brazil
| | - Alexandre J. C. Lanfredi
- NanoBioMAv, Centro de Ciências Naturais e Humanas (CCNH) and Centro de Engenharia,
Modelagem e Ciências Sociais Aplicadas (CECS), Universidade Federal do ABC (UFABC), Avenida dos Estados 5001, Bairro Bangu, 09210-580 Santo André, São Paulo, Brazil
| | - Jeverson T. Arantes
- NanoBioMAv, Centro de Ciências Naturais e Humanas (CCNH) and Centro de Engenharia,
Modelagem e Ciências Sociais Aplicadas (CECS), Universidade Federal do ABC (UFABC), Avenida dos Estados 5001, Bairro Bangu, 09210-580 Santo André, São Paulo, Brazil
| | - Maria
A. Juliano
- Departamento
de Biologia Molecular, Universidade Federal
de São Paulo, Rua 3 de Maio 100, Vila Clementino, 04044-020 São Paulo, São Paulo, Brazil
| | - Iseli L. Nantes
- NanoBioMAv, Centro de Ciências Naturais e Humanas (CCNH) and Centro de Engenharia,
Modelagem e Ciências Sociais Aplicadas (CECS), Universidade Federal do ABC (UFABC), Avenida dos Estados 5001, Bairro Bangu, 09210-580 Santo André, São Paulo, Brazil
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9
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Berengue OM, Chiquito AJ, Pozzi LP, Lanfredi AJC, Leite ER. Electron-phonon scattering in Sn-doped In2O3 FET nanowires probed by temperature-dependent measurements. Nanotechnology 2009; 20:245706. [PMID: 19471074 DOI: 10.1088/0957-4484/20/24/245706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on the structural and electrical characterization of individual Sn-doped In(2)O(3) nanowires. Key information on the nanowire's electron transport such as the carrier's mobility and density are presented. The mobility data was found to decrease as the temperature increases, providing direct evidence of the electron-phonon interaction as the dominant scattering mechanism in this oxide system. The results were confirmed by resistivity measurements and additionally the electron density could be directly calculated providing n = 5 x 10(24) cm(-3), confirming the samples' metallic character.
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Affiliation(s)
- Olivia M Berengue
- Departamento de Física, Universidade Federal de São Carlos, CEP 13565-905, CP 676, São Carlos, São Paulo, Brazil.
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10
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Chiquito AJ, Lanfredi AJC, Oliveira RFMD, Pozzi LP, Leite ER. Electron dephasing and weak localization in Sn doped In(2)O(3) nanowires. Nano Lett 2007; 7:1439-43. [PMID: 17441774 DOI: 10.1021/nl070178k] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We report on (magneto-) transport measurements of individual In2O3 nanowires. We observed that the presence of a weak disorder arising from doping and electron-boundary collisions leads to weak localization of electrons as revealed by the positive magnetoconductivity in a large range of temperatures ( approximately 77 K). From temperature-dependent resistance and magnetoconductivity data, the electron-electron interaction was pointed out as the mechanism responsible for the increase of resistance in the low temperature range and the dominant source of the dephasing at low temperatures. The experimental data provided the phase coherence time tau(phi) approximately T(-2/3) expected for 1D systems, giving consistent support to the mechanisms underlying the weak-localization and electron-electron scattering theories.
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Affiliation(s)
- Adenilson J Chiquito
- Departamento de Física, Universidade Federal de São Carlos, CEP 13565-905, CP 676 São Carlos, São Paulo, Brazil.
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