LASER-INDUCED GRAPHENE PAPER-BASED ELECTRODES FOR ELECTROCHEMICAL DETECTION OF THE PANCREATIC CANCER BIOMARKER CA19-9 IN URINE SAMPLES

Gabriella Onila; Gustavo Gonçalves Dalkiranis Pereira; Andrey Coatrini Soares; Bruno Bassi Millan Torres; Prof. Dra. Débora Gonçalves

Título do Trabalho

Autores

Gabriella Onila
Gustavo Gonçalves Dalkiranis Pereira
Andrey Coatrini Soares
Bruno Bassi Millan Torres
Prof. Dra. Débora Gonçalves

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-2026/1460055-laser-induced-graphene-paper-based-electrodes-for-electrochemical-detection-of-the-pancreatic-cancer-biomarker-c

ISBN

978-65-272-2467-9

Palavras-Chave

Laser-induced graphene (LIG), pancreatic cancer, CA19-9, paper-based electrodes.

Resumo

Pancreatic cancer has one of the highest mortality rates, and its early detection remains a challenge, significantly limiting therapeutic strategies. This research reports the optimization, structural characterization, and biosensing performance of laser-induced graphene (LIG) electrodes fabricated on paper substrates for CA19-9 detection. The formation of interdigitated electrodes (IDEs) was optimized by systematically varying laser power (3–8% of 22 W) and scanning speed (300–800 mm/min). To assess the trade-off between graphene formation and substrate degradation, heatmaps were generated. Based on this, the best condition was achieved at 7% power and 300 mm/min for digit formation, while for the terminals and contacts, the optimized parameters were 6% power and 500 mm/min. Morphological evaluation via scanning electron microscopy (SEM) revealed well-defined porous graphene structures. Energy-dispersive spectroscopy (EDS) confirmed the presence of carbon, oxygen, and calcium, principally. Raman spectroscopy further validated the synthesis of multilayer porous graphene, evidenced by the characteristic D, G, and 2D bands. Spatial Raman analysis of the digits revealed structural heterogeneity, where the central irradiation zone promotes higher ablation compared to the border. Electrochemical impedance spectroscopy (EIS) demonstrated that electrodes (terminal and contacts) produced at 6% power and 500 mm/min exhibited the lowest resistivity values when compared to other conditions. Furthermore, a post-synthesis mechanical pressing step was found to significantly reduce real impedance by increasing the packing density of the graphene sheets. The optimized platform was applied as a capacitive biosensor for the CA19-9 biomarker. The sensing data followed a Langmuir–Freundlich model (R²=0.99), yielding a limit of detection (LOD) of 2.38 U/mL and a limit of quantification (LOQ) of 7.86 U/mL. Preliminary analyses of urine samples suggest that the paper electrodes show promising results for point-of-care applications, particularly for screening above and below the clinical threshold of 37 U/mL. Enhancements in the measurement protocol are needed to develop a calibration curve that can more accurately quantify the biomarker, aligning more closely with the results obtained from the ELISA technique. Acknowledgments: This work was supported by the National Council for Scientific and Technological Development (CNPq, Brazil) (grant numbers 446650/2024-2, 107555/2024-7); National Institute of Organic Electronics INEO/FAPESP/INCT (grant number 314845/2025-9) and São Paulo Research Foundation (FAPESP) (grant numbers 2024/06362-6, 2018/22214-6).

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

ONILA, Gabriella et al.. LASER-INDUCED GRAPHENE PAPER-BASED ELECTRODES FOR ELECTROCHEMICAL DETECTION OF THE PANCREATIC CANCER BIOMARKER CA19-9 IN URINE SAMPLES.. 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-2026/1460055-LASER-INDUCED-GRAPHENE-PAPER-BASED-ELECTRODES-FOR-ELECTROCHEMICAL-DETECTION-OF-THE-PANCREATIC-CANCER-BIOMARKER-C. Acesso em: 10/08/2026