COMPARISON OF SAMPLE PREPARATION METHOD FOR CARBENDAZIM DETECTION VIA SERS

Isabela Bianchi Carvalho; Cibely da Silva Martin Sonvesso; T. A. Oliveira (MS); UNESP; Marcelo José dos Santos Oliveira; Carlos José leopoldo Constantino

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Submission

Paper Title

COMPARISON OF SAMPLE PREPARATION METHOD FOR CARBENDAZIM DETECTION VIA SERS

Authors

Isabela Bianchi Carvalho
Cibely da Silva Martin Sonvesso
T. A. Oliveira (MS); UNESP
Marcelo José dos Santos Oliveira
Carlos José leopoldo Constantino

Modality

Pôster

Subject area

Síntese e caracterização de materiais

Publishing Date

12/12/2023

Country of Publishing

Brasil

Language of Publishing

Inglês

Paper Page

https://www.even3.com.br/anais/workshop-do-ineo-2023/613032-comparison-of-sample-preparation-method-for-carbendazim-detection-via-sers

ISBN

978-65-272-0088-8

Keywords

Carbendazim, SERS, detection, aggregation, sample preparation

Summary

Faced with the impossibility of finding a safe dose for human consumption, the use of the fungicide carbendazim (CBZ) was prohibited by ANVISA in August of 2022 [1]. Therefore, the detection and monitoring of CBZ is of great importance. Among the existing techniques, the SERS technique (surface-enhanced Raman scattering) has often been used for the detection of pesticides [2]. In this work, a comparison was made between multiple standard addition (AMP) and external standard addition (APE) methods and their influence on Ag colloid aggregation and CBZ detection. In the AMP method, aliquots of CBZ solution are added in sequence to the same Ag colloid dispersion. In the APE method, every aliquot of CBZ solution is added to a neat Ag colloid dispersion. The characterization was made by extinction spectroscopy (UV-Vis), dynamic light scattering (DLS) and zeta potential. In the extinction measurements, for the APE method, the appearance of the aggregate band occurs in a concentration close to that by AMP method (1.3x10-6 mol/L) with the maximum intensity ranging between 530 nm (1.7x10-5 mol/L) and 650 nm (4x10-6 mol/L), values lower than those observed for AMP. Besides, the band at 285 nm (transition p-p* of the benzimidazole group) arises from 4.0x10-6 mol/L (concentration close to which it is observed by AMP). For both methodologies, the plasmon band formation occurs at 400 nm, attributed to isolated AgNPs. In the study of the size distribution of AgNPs and aggregates by DLS for APE method, there is a displacement for larger sizes, which is more pronounced at 1.3x10-6 mol/L, with small size variation after this concentration (between 153±74 nm and 199±83 nm). By AMP, on the other hand, the offset to larger sizes happens more continuously. When performing the zeta potential measurements of Ag colloid as a function of CBZ concentration for APE method, the values become less negative, with a more noticeable variation between 1.3x10-6 and 2.4x10-5 mol/L. This indicates aggregation of AgNPs, with the chloride ions surrounding the AgNPs being replaced by CBZ molecules, causing the surface charge to be less negative. Zeta potential values for higher concentrations of APE method become less negative than AMP values. For SERS measurements, the detection was made at close concentrations to both methods (APE: 1.3x10-6 mol/L, AMP: 4.0x10-6 mol/L), with decreasing signal/noise ratio at high concentrations for both cases from 4.0x10-6 mol/L. Therefore, the results of UV-Vis and SERS indicate similar behaviors for both methods, while those of DLS and zeta potential show divergences, and further studies are needed for a more conclusive analysis of the aggregation mechanism. 1https://agenciabrasil.ebc.com.br/saude/noticia/2022-08/anvisa-proibe-uso-do-fungicida-carbendazim-em-produtos-agrotoxicos. 2Rubira, R.J.G. et al. S. Vib.Spectrosc. 2021, 114, 103245. FAPESP (2021/02746-6 and 2018/22214-6), CNPq, INCT/INEO, CAPES.

Title of the Event: Workshop do INEO 2023
City of the Event: Nazaré Paulista
Title of the Proceedings of the event: Anais do Workshop INEO 2023
Name of the Publisher: Even3
Means of Dissemination: Meio Digital

How to cite

CARVALHO, Isabela Bianchi et al.. COMPARISON OF SAMPLE PREPARATION METHOD FOR CARBENDAZIM DETECTION VIA SERS.. In: Anais do workshop INEO 2023. Anais...Nazaré Paulista(SP) Hotel Estância Atibainha, 2023. Available in: https//www.even3.com.br/anais/workshop-do-ineo-2023/613032-COMPARISON-OF-SAMPLE-PREPARATION-METHOD-FOR-CARBENDAZIM-DETECTION-VIA-SERS. Access in: 15/05/2025