A novel GLUT-4 electrochemical immunosensor based on a poly(thionine)-gold nanoparticle nanocomposite: Combining complex capacitance and dissolved oxygen to obtain an analytical signal

Detection of glucose transporter 4 (GLUT4) is essential for understanding various physiological and pathological processes. This work reports the development of a novel electrochemical immunosensor for the direct detection of GLUT4, employing dissolved oxygen as a redox probe. This molecular oxygen-...

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Detalles Bibliográficos
Autores: Olean-Oliveira, André, Seraphim, Patrícia Monteiro [UNESP], Portugal, Miquéias L. [UNESP], Teixeira, Marcos F.S. [UNESP]
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:Brasil
Institución:Universidade Estadual Paulista (UNESP)
Repositorio:Repositório Institucional da UNESP
Idioma:inglés
OAI Identifier:oai:repositorio.unesp.br:11449/298662
Acceso en línea:http://dx.doi.org/10.1016/j.bios.2025.117219
https://hdl.handle.net/11449/298662
Access Level:acceso abierto
Palabra clave:Anti-GLUT4
Electrochemical impedance spectroscopy
Glucose transporters
Gold nanoparticle polymer
Immunosensor
Physiological protocol
Descripción
Sumario:Detection of glucose transporter 4 (GLUT4) is essential for understanding various physiological and pathological processes. This work reports the development of a novel electrochemical immunosensor for the direct detection of GLUT4, employing dissolved oxygen as a redox probe. This molecular oxygen-sensitive response is mediated by a redox-conductive polymer based on thionine. The sensor platform was fabricated via a one-step electropolymerization of thionine and gold nanoparticles (AuNPs) onto a platinum screen-printed electrode (Olean-Oliveira et al., 2022a). The immunosensor was then constructed by physical adsorption of a GLUT4 antibody onto the poly(thionine)-AuNP composite surface. This label-free approach eliminates the need for secondary antibodies or enzymes. The immunosensor performance was evaluated using electrochemical impedance spectroscopy (EIS). The sensing mechanism relies on impedance changes; increasing GLUT4 concentrations lead to increased impedance due to enhanced surface blocking upon GLUT4-antibody binding. This interaction impedes oxygen diffusion to the polymer redox sites, resulting in increased electrical resistance. Analysis of the redox capacitance as a function of frequency demonstrates a decrease in the capacitive arc with increasing GLUT4 concentration.