Banca de DEFESA: ALEX PEDRO DE ARAÚJO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ALEX PEDRO DE ARAÚJO
DATE: 29/07/2024
TIME: 14:00
LOCAL: VIRTUAL
TITLE:

DEVELOPMENT OF ELECTROANALYTIC METHODS FOR DETECTION AND QUANTIFICATION OF THE BIOMARKERS 7-METHYL-GUANINE AND 3-METHYL-ADENINE, USING PULSE VOLTAMETRIC TECHNIQUES

KEY WORDS:

DNA Methylation, Biomarkers, 7-methylguanine, 3-methyladenine, Differential Pulse Voltammetry, Screen Printed Carbon Electrodes

PAGES: 81
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Analítica
SPECIALTY: Eletroanalítica
SUMMARY:

DNA methylation is a crucial epigenetic process that plays an essential role in regulating gene expression. However, errors in DNA methylation or repair can lead to mutations and have been associated with several human diseases, including diabetes, Alzheimer's, neurodegenerative diseases and several types of cancer. This work aimed to develop electroanalytical methods for the identification and quantification of methylated DNA species, 7-methylguanine (7-mGua) and 3-methyladenine (3-mAde), using pulse voltammetric techniques, such as differential pulse voltammetry (DPV) and square wave voltammetry (SWV). The simultaneous electrocatalytic response of 7- mGua and 3-mAde on anodically functionalized carbon printed electrode (aSPCE) by DPV was investigated. 7-mGua and 3-mAde were oxidized at different potential values, in an acidic medium (pH = 4.5) 7-mGua was oxidized at E = 0.81 V and 3-mAde at E = 1, 18 V and in a neutral medium the 7-mGua at E = 0.70 V and 3-mAde at E = 1.01 V, indicating excellent separation and the possibility of simultaneous detection between these species. Different experimental factors were then investigated for the development of an electroanalytical method for simultaneous quantification of 7-mGua and 3-mAde by DPV and aSPCE, such as the composition and pH of the aqueous support electrolyte, adsorption and influence of possible interferents (guanine, adenine, thymine and cytosine). Under optimized conditions, the method achieved in an acidic medium (pH = 4.5) an analytical curve for determining 7-mGua in the range of 1.00–8.00 μmol L−1 (r = 0.997) and limit of detection (LOD) of 0.63 μmol L−1 ; for 3- mAde from 1.00 to 8.00 μmol L−1 (r = 0.997) and LOD from 0.61 μmol L−1 . In neutral medium, the analytical data achieved were for 7-mGua in the range of 0.50–5.00 μmol L −1 (r = 0.995) and LOD of 0.63 μmol L−1 ; for 3-mAde from 5.00 to 10.00 μmol L−1 (r = 0.996) and LOD from 0.71 μmol L−1 . A new sensitive, selective and rapid electrochemical method for simultaneous detection and quantification of the biomarkers 7-mGua and 3-mAde using DPV and an aSPCE was then proposed. The possibility of detecting and quantifying 7-mGua on conventional platinum and gold solid electrodes was also explored.

COMMITTEE MEMBERS:
Presidente - SEVERINO CARLOS BEZERRA DE OLIVEIRA
Interno - MARCILIO MARTINS DE MORAES
Externo à Instituição - WILLIAME FARIAS RIBEIRO - UFPB
Externo à Instituição - RAPHAEL FONSÊCA DO NASCIMENTO - UNICAP