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Rodrigo Gribel Lacerdahttp://lattes.cnpq.br/9333015140693096Ingrid David BarcelosCristiano Fantini LeiteAlexandre Reily RochaMário Sérgio de Carvalho MazzoniCecília de Carvalho Castro e Silvahttp://lattes.cnpq.br/1163431376059357Leonel Muniz Meireles2020-10-27T19:23:24Z2020-10-27T19:23:24Z2020-08-07http://hdl.handle.net/1843/34316https://orcid.org/0000-0001-6550-7804Grafeno é um material bidimensional (2D) composto apenas por átomos de carbono, que tem sido amplamente estudado devido às suas propriedades elétricas, mecânicas e ópticas. A combinação deste material com algumas técnicas de caracterização tem alcançado importantes conquistas, especialmente no desenvolvimento de biossensores. No entanto, o uso do grafeno para tais fins, se inicia com o desafio de entender e dominar todas as propriedades deste material na presença de meios líquidos. Desta forma, a primeira proposta desta tese consiste em aprimorar o entendimento das propriedades elétricas do grafeno, quando este passa a estar na interface ar/água. Realizamos esse estudo através da construção de um dispositivo que nos permitiu estudar a interação do grafeno suspenso sobre água, ou seja, sem a presença de substratos. Observamos que, a diminuição abrupta da resistividade do grafeno suspenso na presença de água é de natureza eletromecânica, com um efeito de transferência de carga de magnitude muito menor, caso existam, que efeitos mecânicos. Esse resultado não apenas esclarece alguns enigmas científicos básicos (transferência de carga da água para o grafeno), mas também desbloqueia novas aplicações para sistemas fluídicos híbridos de baixa dimensão. Em uma segunda abordagem, fabricamos uma plataforma de microburacos para análise de biomateriais em ambientes líquidos com espectroscopia de infravermelho realizada em nanoescala. Nesse segundo trabalho, a partir da interface grafeno/líquido, juntamente com a técnica SINS (do ingles Synchrotron Infrared Nano-spectroscopy) obtemos a “impressão digital” infravermelha de fluidos, biológicos e químicos, tais como o Dimetil Sulfóxido (DMSO), Fosfato dipotássico (KH2PO4) e ácido pirenobutanóico éster succinimidílico (PBSE). Além disso, demonstramos a nanoespectroscopia de fragmentos de albumina de soro humano (HSA) em água com uma visão clara das assinaturas espectrais de proteínas e suas estruturas secundárias através da resposta vibracional das bandas amidas I-II.Graphene is a two-dimensional (2D) material composed only of carbon atoms, which has been widely studied due to its electrical, mechanical and optical properties. The combination of this material with some characterization techniques has achieved important achievements, especially in the development of biosensors. However, the use of graphene for such purposes begins with the challenge of understanding all the properties of this material in the presence of liquid media. Thus, the first proposal of this thesis is to improve the understanding of the electrical properties of graphene, when it becomes at the air/water interface. We conducted this study by building a device that allowed us to study the interaction of graphene suspended over water, that is, without the presence of substrates. We observed that the abrupt decrease in the resistivity of suspended graphene in the presence of water is electromechanical in nature, with a load transfer effect of much less magnitude, if any, than mechanical effects. This result not only clears up some basic scientific enigmas (transferring charge from water to graphene), but it also unlocks new applications for small fluid hybrid systems. In a second approach, we manufacture a micro-hole platform for analyzing biomaterials in liquid environments with nanoscale infrared spectroscopy. In this second work, using the graphene / liquid interface, together with the SINS technique (Synchrotron Infrared Nano-spectroscopy), we obtain the infrared “fingerprint” of fluids, biological and chemical, such as Dimethyl Sulfoxide (DMSO), Potassium dihydrogen phosphate (KH2PO4) and pyrenobutanoic acid succinimidyl ester (PBSE). In addition, we demonstrate the nanospectroscopy of fragments of human serum albumin (HSA) in water with a clear view of the spectral signatures of proteins and their secondary structures through the vibrational response of the amide bands I-II.CNPq - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas GeraisCAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorporUniversidade Federal de Minas GeraisPrograma de Pós-Graduação em FísicaUFMGBrasilICX - DEPARTAMENTO DE FÍSICAGrafenoInterfacesDispositivos nanoeletrônicosGrafenoInterfacesNano-FTIRNano-devicesEstudo e aplicações da interface grafeno-águainfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFMGinstname:Universidade Federal de Minas Gerais (UFMG)instacron:UFMGORIGINALTese-Leonel-VersaoFinal_.pdfTese-Leonel-VersaoFinal_.pdfapplication/pdf14987403https://repositorio.ufmg.br/bitstream/1843/34316/1/Tese-Leonel-VersaoFinal_.pdf224054a18d7838b90834a2817382e6aaMD51LICENSElicense.txtlicense.txttext/plain; charset=utf-82119https://repositorio.ufmg.br/bitstream/1843/34316/2/license.txt34badce4be7e31e3adb4575ae96af679MD521843/343162020-10-27 16:23:24.412oai:repositorio.ufmg.br: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Repositório InstitucionalPUBhttps://repositorio.ufmg.br/oaiopendoar:2020-10-27T19:23:24Repositório Institucional da UFMG - Universidade Federal de Minas Gerais (UFMG)false
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