SÍNTESE DE SENSORES DE TiO2-XNT/CuXO PARA A QUANTIFICAÇÃO DO PESTICIDA GLIFOSATO

• Autor(a) principal: OHSE, SAMANTHA TORRES
• Data de Publicação: 2024
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do UNICENTRO
• Texto Completo: http://tede.unicentro.br:8080/jspui/handle/jspui/2161
• topic: TiO2NT; Óxidos Mistos de Cobre; Sensor Eletroquímico; Autodopagem; Voltametria de Pulso Diferencial; TiO2NT; Mixed Copper Oxides; Electrochemical Sensor; Self-doping; Differential Pulse Voltammetry; CIENCIAS EXATAS E DA TERRA::QUIMICA

Due to the ease with which the pesticide glyphosate reaches aquatic matrices, monitoring and quantifying this substance have become essential. Thus, an electrochemical sensor was developed, using as a substrate nanotubular TiO2 films, modified with Ti3+ ions and nanostructured mixed copper oxides (CuXO) for glyphosate quantification using voltametric electroanalytical techniques. The nanotubular structure was synthesized through potentiostatic anodization, and the material’s surface modification was carried out by electrodeposition of copper oxides and reduction of Ti4+ ions to Ti3+ through cathodic reduction. After optimizing the experimental conditions, the method was validated for lake water sample, with the sensor exhibiting a significant matrix effect, indicating the need to perform a calibration curve by standard addition. The sensor was able to quantify traces of glyphosate in a linear working range of 0.55 to 1000.00 pmol L-1, obtaining a significant logarithmic linear regression, and showing no lack off it to the model at a 95.00% confidence level. In residual plot analysis and Grubbs, Cochran and Durbin-Watson tests, no outliers were detected, and homoscedasticity of variances was confirmed. Low limits of detection (LOD = 3,44x10-3 pmol L-1) and quantification (LQ = 0,27 pmol L-1) were obtained when applied to lake water sample, values below those reported in the literature for electrochemical sensors. Method selectivity was evaluated through recovery studies, yielding values between 54.91 and 132.72%, within the limits stipulated by validation guidelines. Repeatability study demonstrated that the sensor can be used in up to 12 consecutive readings without compromising its performance, while stability study indicated no influence on the sensor’s response over the storage time. Therefore, it was demonstrated that the developed sensor shows promising results, highlighting its potential application in aquatic matrices to contribute to environmental monitoring.