Autor(es)

Hassan, Ayaz ^[1] ; Macedo, Lucyano J. A. ^[1] ; Mattioli, Isabela A. ; Rubira, Rafael J. G. ^[2] ; Constantino, Carlos J. L. ^[2] ; Amorim, Rodrigo G. ^[3] ; Lima, Filipe C. D. A. ^[4] ; Crespilho, Frank N. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Inst Chem, BR-13560970 Sao Paulo - Brazil

^[2] Sao Paulo State Univ UNESP, Phys Dept, Campus Presidente Prudente, BR-19060900 Sao Paulo - Brazil

^[3] Fluminense Fed Univ UFF, Phys Dept, ICEx, BR-27213145 Volta Redonda, RJ - Brazil

^[4] Fed Inst Educ Sci & Technol Sao Paulo, Campus Matao, BR-15991502 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Electrochimica Acta; v. 376, APR 20 2021.
• Citações Web of Science: 0

Resumo

Graphene-based vertical electrodes may have applications in biomolecular recognition for producing low-cost biodevices with high electronic conductivity. However, they are unsuitable for measuring small interfacial capacitance variations because graphene is mostly composed of basal sp(2) carbon surface, which limits its sensitivity as an electrochemical biosensor. Herein, we introduce a monolayer graphene based three-component vertically designed (TCVD) device composed of ferrocene adsorbed on monolayer graphene supported on lithographically designed gold subsurface on silicon wafer. Ferrocene is the top layer that promotes reversible redox communication with the electrolyte, while graphene-gold is the strategically projected layer underneath. This system exhibits an enhanced chemical reactivity by allowing the electrochemical attachment of the larger amount of the organic functional groups on its surface and faster electrochemical response to an inner-sphere redox probe in the solution. Bader charge analysis indicated that gold donates electronic density to the graphene surface, thereby significantly increases the charge transfer exchange rate with ferrocene. Based on density functional theory (DFT) simulation and spectromicroscopy data, it was realized that the interaction between gold and graphene is through physical adsorption with a slight change in the Fermi's level of graphene. The TCVD device was used to detect the adsorption of double-stranded DNA and DNA hybridization in solutions. Based on capacitance calculation measurements, DNA hybridization in nanomolar range with sensitivity four times higher and limit of detection (LOD) three times lower as compared to Fc/Gr/SiO2/Si, which was effortlessly detected. This result is promising since 3.0 mu F cm(-2) is the limit of quantum capacitance for bare graphene. Notably, these results open a new possibility for next-generation TCVD bioelectronics based on van der Waals surfaces, while further innovation and material scrutiny may lead to the achievement of TCVD devices with robust biomolecular recognition abilities. (C) 2021 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 18/22214-6 - Rumo à convergência de tecnologias: de sensores e biossensores à visualização de informação e aprendizado de máquina para análise de dados em diagnóstico clínico
• Beneficiário: Osvaldo Novais de Oliveira Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 17/20493-2 - Estudo de metaloenzimas por eletroquímica acoplada à espectroscopia vibracional
• Beneficiário: Lucyano Jefferson Alves de Macêdo
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 19/12053-8 - Eletrodos de alto desempenho aplicados em baterias orgânicas e em biocélulas a combustível
• Beneficiário: Frank Nelson Crespilho
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 19/15333-1 - Células híbridas bio-foto-eletroquímicas para conversão de energia solar
• Beneficiário: Frank Nelson Crespilho
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/11071-0 - Desenvolvimento e aplicação de eletrodos compósitos impressos descartáveis à base de nanopartículas metálicas e grafite-poliuretana
• Beneficiário: Isabela Alteia Mattioli
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto