DEVELOPMENT OF AN ELECTROCHEMICAL BIOSENSOR FOR THE QUANTITATIVE DETECTION OF BACTERIAL GENOME

Felipe Zahrebelnei; Carolina Weigert Galvão; Rafael Mazer Etto; Christiana Andrade Pessoa; Karen Wohnrath

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Paper Title

DEVELOPMENT OF AN ELECTROCHEMICAL BIOSENSOR FOR THE QUANTITATIVE DETECTION OF BACTERIAL GENOME

Authors

Felipe Zahrebelnei
Carolina Weigert Galvão
Rafael Mazer Etto
Christiana Andrade Pessoa
Karen Wohnrath

Modality

Pôster

Subject area

Biossensores / Biomoléculas

Publishing Date

12/12/2023

Country of Publishing

Brasil

Language of Publishing

Inglês

Paper Page

https://www.even3.com.br/anais/workshop-do-ineo-2023/613339-development-of-an-electrochemical-biosensor-for-the-quantitative-detection-of-bacterial-genome

ISBN

978-65-272-0088-8

Keywords

Electrochemical biosensor, Gold nanoparticle, Carbon nanotube

Summary

Biosensors are devices that quantitatively detect analytes through specific interaction with biomolecules present in their structure. This interaction is transformed into a signal, such as an electrical signal. (1) In this work, the development of an electrochemical biosensor for the quantitative detection of the bacterial genome is reported. This biosensor was developed using glassy carbon electrode (GCE) previously oxidized by chronoamperometry, followed by its modification using a nanocomposite formed by oxidized carbon nanotubes (CNT) and gold nanoparticles stabilized in a silsesquioxane polymer (AuNPs-SiPy). After constructing the platform, the modified electrode was incubated for 60 minutes with a thiolated single strand DNA, with a sequence of specific nitrogenous bases for hybridization with the bacterial genome. Finally, the biosensor was incubated in a sample containing the bacterial genome for 45 minutes, for hybridization of the genome with the probe. The hybridization process was detected by square wave voltammetry (SWV). The construction of the biosensor was analyzed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) where [Fe(CN)6]3-/4- was used as an electrochemical probe. After oxidation of the GCE, a decrease in the anode (ipa) and cathode (ipc) peak current values is observed, as well as an increase in the load transfer resistance value (Rct). This is due to the repulsion between the electrochemical probe and the charge on the oxidized surface of the electrode (2). After modifying the electrode with the nanocomposite, there was a significant increase in the ipa and ipc values, and a large decrease in the Rct value, indicating a decrease in the repulsion between the probe and the electrode, as well as an improvement in the electrochemical response due to the electrocatalytic and conductive properties of the material. After incubation of the platform with the probe, there is again a decrease in ipa and ipc, due to the repulsion between the phosphate groups of the single strand of DNA with the electrochemical probe, both negatively charged, also resulting in an increase in the value of Rct. Finally, after hybridization with the bacterial genome, the amount of DNA strands on the electrode surface is increased, further increasing the repulsion between the electrode surface and the electrochemical probe, decreasing the ipa and ipc values by 27.6% and 26.9%, respectively, and increasing the Rct value by 106.5%. To carry out the quantitative detection of the bacterial genome, the biosensor was incubated in samples containing different concentrations (5.0 to 624.5 ng µL-1) of the genome, and the ipa value was verified in each one, using SWV. In this way, the analytical curve was obtained with its respective linear correlation equation ipa = -16.902 log [analyte] + 161.101 with R2=-0.999. Detection and quantification thresholds were calculated as 1.11 ng µL-1 and 1.37 ng µL-1, respectively. A negative control study was also carried out, which attested to the selectivity of the biosensor. Studies were also carried out with a real sample, where it was possible to detect the genome in a sample containing metagenomic DNA from the soil and also verify the stability of this biosensor for 7 weeks. Acknowledgment: To the organizing committee of this Workshop, to INEO, Capes and CNPq, to the laboratories GDEM, GDMIT, LABMOM and CLabmu from UEPG. (1) THÉVENOT, D. R. et al. Electrochemical biosensors: recommended definitions and clas-sification. Analytical Letters, v. 34, n. 5, p. 635-659, 2001. (2) BONANNI, A.; DEL VALLE, M. Use of nanomaterials for impedimetric DNA sensors: a review. Analytica chimica acta, v. 678, n. 1, p. 7-17, 2010.

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

ZAHREBELNEI, Felipe et al.. DEVELOPMENT OF AN ELECTROCHEMICAL BIOSENSOR FOR THE QUANTITATIVE DETECTION OF BACTERIAL GENOME.. 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-2023/613339-DEVELOPMENT-OF-AN-ELECTROCHEMICAL-BIOSENSOR-FOR-THE-QUANTITATIVE-DETECTION-OF-BACTERIAL-GENOME. Access in: 05/12/2024