Fabrication of rGO Compounds and Electrodes for Application in Quantum Capacitance-Based Biosensors

• Grant number: 24/07625-0
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: October 01, 2024
• End date: September 30, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Paulo Roberto Bueno
• Grantee: Isabella Sampaio do Nascimento
• Supervisor: Arben Merkoci
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Institution abroad: Catalan Institute of Nanoscience and Nanotechnology (ICN2), Spain
• Associated to the scholarship: 20/14756-3 - Electrochemical capacitive point-of-care viral detection platform, BP.PD

Abstract

The Nanobionics research group has pioneered the study of electron transfer within a quantum electrodynamics context in which molecules or nanoscale entities can be applied throughout the quantum rate theory. By leveraging this theory, from which Marcus's ET transfer theory is a part, we can precisely measure the quantum capacitance of compounds being parts of electrodes using electrochemical impedance spectroscopy methods, unlocking insights into the electronic structure of these compounds. Providing that quantum capacitance is significantly affected by interface events like biorecognition, it emerges as a pivotal parameter for transducer signaling in the biological environment. The Nanobionics research group has successfully applied this methodology to investigate molecular films containing redox-tagged peptides, single-layer graphene, and quantum dots. For this purpose, reduced graphene oxide (rGO) electrodes have attracted significant interest due to their supercapacitance associated with the pseudocapacitive charge storage process which ultimately is a phenomenon contained and explained by the quantum rate theory. However, traditional rGO electrode fabrication methods involving chemical or hydrothermal reduction of graphene oxide, followed by patterning through lithography or printing techniques, suffer from complexity, reproducibility, and scalability issues. To overcome this, Merkoçi's group has developed a cutting-edge methodology in which graphene oxide is reduced and patterned simultaneously through laser engraving and transferred using a stamp transfer technique onto a desired substrate. This breakthrough approach yields rGO electrodes with superior defect control and scalability. Therefore, this research proposal aims to utilize the methodology developed by Merkoçi's group to fabricate rGO electrodes and explore quantum capacitance as a transducer signal for ultra-sensitive molecule detection, such as clinically relevant proteins or small molecules. Supervised by Professor Arben Merkoçi, a leading expert in nanomaterial-based biosensors, this project holds the promise of groundbreaking advancements.