Spectroelectrochemical investigation of sensors and biosensors based on photoactivated plasmonic nanoparticles

• Grant number: 23/01689-4
• Support Opportunities: Regular Research Grants
• Duration: May 01, 2023 - April 30, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Juliana Cancino Bernardi
• Grantee: Juliana Cancino Bernardi
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Plasmonic nanomaterials of different sizes, shapes and properties have been developed in recent decades for different applications. Among these, photothermal therapy makes use of the localized surface plasmon resonance (LSPR) effect of metallic nanoparticles to generate rapid localized heating from the coherent movement of electrons in the conduction band of the material. In addition to the photothermal effect, the collective oscillation of conduction band electrons produces a local electric field at the surface of the nanoparticle, generating free electrons that can be excited to energy levels much higher than the Fermi level. The recent use of photoactivation of plasmonic nanoparticles in electrochemical systems offers advantages as it increases the rate and selectivity of chemical reactions, as well as the detection of analytes at reduced concentrations. Understanding the electrocatalytic effect and the photocatalytic contributions of plasmonic nanoparticles can favor the development of even more effective and innovative detection systems. The challenge requires an interdisciplinary approach, combining spectroscopic and electrochemical investigation of these heterogeneous systems. In this context, the emphasis of this regular project is on developing and investigating light-activated transducer platforms applied to electroanalysis. The electrocatalytic responses of sensors and biosensors based on the photoactivation of plasmonic gold nanoparticles of three different morphologies (gold nanorods - AuNRs, gold nanoflowers - AuNFs and gold nanobipyramids - AuBPs) will be evaluated. For this, each plasmonic nanoparticle will be immobilized on electrodes as self-assembled films combined with conductive polymers. Spectroelectrochemical measurements of these systems will be systematically explored before and after laser application to assess the impact of photoactivation on increasing the catalytic activity of sensor and biosensor systems based on the enzyme redox alcohol dehydrogenase. We emphasize that this theme is unprecedented in electroanalysis and that the proponent has sufficient know-how in the area to conduct the research. Finally, we emphasize that this project will provide the establishment of a solid line of research in Bioanalytical Nanosystems in the Chemistry Department of the Faculty of Philosophy, Sciences and Letters of Ribeirão Preto/USP, where the applicant was recently hired as a professor. (AU)