Quantum Rate Theory Aproach: Advancing To Chemo-And Biosensing Aplications

• Grant number: 25/07551-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: August 01, 2025
• End date: July 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Eduardo Maffud Cilli
• Grantee: Sarah Tolentino Rocha Brandão
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Associated research grant: 24/02000-2 - Principles and methods of low energy quantum electrodynamics, AP.TEM

Abstract

Quantum Rate Theory (QRT) has been proposed to investigate the electrodynamics of electron transfer processes in mesoscopic systems at electrodes. This theory has demonstrated the relativistic nature of the quantum charge state of electroactive systems, including redox switches (1D), graphene monolayers (2D) and semiconductor nanostructures. Recently, this theory has been applied to investigate the characteristics of peptide monolayers and the resonance dynamics of push-pull conjugated heterocyclic systems, revealing details about theirelectronic structures. Push-pull conjugated heterocyclic systems are a group of organic molecules with structures that confer exceptional optical and electronic properties, which are of interest for molecular electronics, optoelectronic materials, and sensors. These molecules are formed by an electron donor group (D) and an electronacceptor group (A) connected by a conjugated bridge. This arrangement is responsiblefor the difference in electronegativity between the two parts of the molecule, which leads to a polarized distribution of the electron that can result in an intermolecular charge transfer (ICT). This relationship between the electronic structure of these systems and the electrical properties can be explored in the field of chemosensor development since the modification of push-pull molecules allows the adjustment of the physicochemical properties. Molecules derived from imidazole, indole, phenanthrolineand peptide groups are being used in optical chemosensors. However, the expansion of the system requires studies. QRT allows access not only to the electronic structure, but also to the disturbances caused by molecular recognition events. Thus, through quantum impedance spectroscopy, the quantum capacitance that provides the density of states (DOS) of push-pull systems is measured, which makes it possible to access the quantum properties in the laboratory in a simple manner without the need for extreme conditions such as low temperatures and vacuum. Therefore, the objective of this work is todevelop quantum sensor platforms whose detection will be based on the relativistic electrodynamic properties of the molecules, which will be analyzed by QRT as a transduction signal. For this purpose, the design, synthesis and characterization of conjugated heterocyclic structures and peptide structures for the fabrication of monolayers on gold and graphene electrodes will be carried out. The design of theheterocyclic structures will consider the incorporation of indole, imidazole and terpyridine derivatives and peptides, in addition to the functionalization with carboxylgroups for the binding of biological molecules such as enzymes, DNA and antibodies. The study of the detection of molecules of environmental and health importance, mainly virus, will be the final objective to be achieved.