Amplifying sensing performance through gold micropatterns-induced modulation of graphene's vertical electron transfer

Author(s)

Hassan, Ayaz ; Colombo, Rafael N. P. ; Iost, Rodrigo M. ; Crespilho, Frank N.

• Document type: Journal article
• Source: Electrochimica Acta; v. 466, p. 9-pg., 2023-08-25.

Abstract

High-quality graphene monolayers exhibit limited vertical electron transfer properties due to their inert basal plan structure, hampering their use in electrochemical sensing devices. Overcoming this limitation while maintaining the graphene's basal plane electrical conductivity is crucial for developing sensitive and efficient electrochemical sensors. In this study, we demonstrate that incorporating a gold support beneath graphene enhances its electrochemical activity by facilitating effective hybridizations between carbon atoms in graphene and gold atoms. To achieve this, micrometer-sized gold micropatterns were fabricated on Si/SiO2 substrates to support the graphene monolayer. The presence of gold significantly improved the electrochemical activity of graphene towards redox probes in solution (ferri-/ferrocyanide) as well as for adsorbed ferrocene, indicating a synergistic effect between graphene and gold. We further investigated the adsorption effects of double-stranded DNA on pristine graphene, bare gold, and graphene with a gold underlayer, revealing that the graphene-gold combination achieved a significantly lower limit of detection for DNA hybridization events, surpassing the other configurations. These findings highlight the importance of appropriate substrate selection in the design of graphene-based electrochemical sensors, particularly in the context of DNA recognition events. The proposed approach of incorporating a gold support beneath graphene holds promise for enhancing the performance of electrochemical sensing devices without compromising the intrinsic properties of graphene. (AU)

• FAPESP's process: 19/12053-8 - High performance electrodes applied in organic batteries and in biofuel cell
• Grantee: Frank Nelson Crespilho
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/15333-1 - Bio-photo-electrochemical hybrid cells for solar energy conversion
• Grantee: Frank Nelson Crespilho
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/22214-6 - Towards a convergence of technologies: from sensing and biosensing to information visualization and machine learning for data analysis in clinical diagnosis
• Grantee: Osvaldo Novais de Oliveira Junior
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 21/05665-7 - Development of Van der Waals surfaces for application in biodevices
• Grantee: Rafael Neri Prystaj Colombo
• Support Opportunities: Scholarships in Brazil - Post-Doctoral