EXPLORING NON-FARADAIC APPROACHES IN APTAMER-BASED ELECTROCHEMICAL BIOSENSORS

Renê Santos de Amorim; Pablo Serrano (PD); UFSC; Matheus Ferrari (IC); UFSC; Maria Luisa Sartorelli; Ivan H Bechtold

Todos os Trabalhos

Trabalho

Título do Trabalho

EXPLORING NON-FARADAIC APPROACHES IN APTAMER-BASED ELECTROCHEMICAL BIOSENSORS

Autores

Renê Santos de Amorim
Pablo Serrano (PD); UFSC
Matheus Ferrari (IC); UFSC
Maria Luisa Sartorelli
Ivan H Bechtold

Modalidade

Pôster - resumo

Área temática

Sensores e biossensores

Data de Publicação

27/05/2026

País da Publicação

Brasil

Idioma da Publicação

pt-BR

Página do Trabalho

https://www.even3.com.br/anais/workshop-do-ineo-2026/1462804-exploring-non-faradaic-approaches-in-aptamer-based-electrochemical-biosensors

ISBN

978-65-272-2467-9

Palavras-Chave

Saxitoxin (STX), Non-faradaic EIS, Biossensors, Organic Electronics

Resumo

The analysis of interfacial responses in electrochemical biosensors using Electrochemical Impedance Spectroscopy (EIS) is inherently complex, as traditional data fitting via equivalent electrical circuits often encounters physical ambiguities due to time-constant dispersion on the electrode surface. Furthermore, these methods typically rely on external redox mediators, which increase experimental complexity and requires the use of toxic agents.[1] To overcome these obstacles, a model-free mathematical approach is proposed, utilizing a differential analysis in the frequency domain to evaluate a generalized capacitance (Cgpe), which directly converts impedance spectra into effective capacitance spectra.[2] This study applies this non-faradaic approach to a biosensing system to detect saxitoxin (STX), a very harmful cyanotoxin. Screen-printed electrodes (SPEs) are functionalized with aptamers, focusing on mapping the intrinsic capacitive changes at the electrode-electrolyte interface during molecular recognition. When STX binds to the immobilized aptamers, a conformational restructuring alters the electrical double layer properties, allowing the method to rigorously isolate these interfacial variations. Consequently, the use of generalized capacitance confirms the feasibility of non-faradaic STX aptasensors by providing a robust, direct, and highly sensitive thermodynamic metric, which eliminates the need for toxic mediators as well. Preliminary results demonstrate that Cgpe offers a good analytical signal when compared to traditional impedance analysis, aligning with findings that alternative electrical parameters significantly enhance the accuracy and sensitivity of impedimetric sensors.[3] By capturing dielectric shifts in a non-faradaic regime, this approach facilitates the development of sensing platforms highly suitable for point-of-care applications. Acknowledgements: "The authors would like to thank INEO and the Brazilian funding agencies FAPESP (process nº 2025/27044-5) and CNPq (process nº 408449/2024-1). This study was financed in part by CAPES (Finance Code 001), CNPq (140223/2023-1 ) and FAPESC. The authors also thank UFSC and PPGQ-UFSC for institutional support and facilities." References: [1] PATEL, R. et al. Part I: Non-faradaic electrochemical impedance-based DNA biosensor for detecting phytopathogen – Ralstonia solanacearum. Bioelectrochemistry, [s. l.], v. 153, 108492, 2023. [2] SARTORELLI, M. L. et al. Model-free capacitance analysis of electrodes with a 2D+1D dispersion of time constants. Electrochimica Acta, [s. l.], v. 390, 138796, 2021. [3] AMORIM, R. S. et al. Improving accuracy and reliability of an electrochemical impedance spectroscopy aptamer-based biosensor. Results in Chemistry, [s. l.], v. 7, 101314, 2024.

Título do Evento: Workshop do INEO 2026
Cidade do Evento: Nazaré Paulista
Título dos Anais do Evento: Anais do Workshop do INEO 2026
Nome da Editora: Even3
Meio de Divulgação: Meio Digital

Como citar

AMORIM, Renê Santos de et al.. EXPLORING NON-FARADAIC APPROACHES IN APTAMER-BASED ELECTROCHEMICAL BIOSENSORS.. In: Anais do Workshop do INEO 2026. Anais...Nazaré Paulista(SP) Hotel Estância Atibainha, 2026. Disponível em: https//www.even3.com.br/anais/workshop-do-ineo-2026/1462804-EXPLORING-NON-FARADAIC-APPROACHES-IN-APTAMER-BASED-ELECTROCHEMICAL-BIOSENSORS. Acesso em: 10/08/2026