Modificação química de ciclodextrina e quitosana para aplicações analíticas
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Data
2021-02-11
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Universidade Estadual Paulista (Unesp)
Resumo
O presente trabalho descreve a modificação química resultante da interação da β- ciclodextrina com dendrímeros PAMAM G.0 e G.3 e da quitosana, com complexos bimetálicos eletroativos. Após a preparação e caracterização espectroscópica dos materiais bimetálicos estudados (Cd-PAMAM G.0-Ag/Fe, Cd-PAMAM G.0-Cu/Fe, Cd-PAMAM G.3-Cu/Fe, CuFeCHT e AgFeCHT), realizou-se um estudo sistemático sobre o comportamento voltamétrico desses materiais, empregando técnicas eletroquímicas, tais como: voltametria cíclica (VC) e voltametria de onda quadrada (VOQ), utilizando para isso eletrodos de pasta de grafite. Adicionalmente esses materiais bimetálicos foram testados na detecção de alguns analitos de interesse biológico e ambiental tais como: isoniazida, dopamina e 4- clorofenol. Os eletrodos de pasta de grafite contendo os materiais do tipo Cd-PAMAM mostraram-se sensíveis a concentrações de dopamina, isoniazida e 4-clorofenol e os materiais a base de quitosana (CHT) mostraram-se sensíveis a concentrações de isoniazida e 4-clorofenol. Após os testes de eletrooxidação catalítica dessas substâncias, realizou-se uma investigação sobre a influência dos principais interferentes no método de detecção, sendo que a interferência observada não se mostrou analiticamente significativa. Avaliouse também a recuperação destas substâncias a partir de amostras de urina sintética. Analisando e confrontando os melhores valores de limite de detecção, sensibilidade amperométrica e eficiência na recuperação em amostras reais, os materiais que se destacaram foram: Cd-PAMAM G.0-Cu/Fe na detecção de isoniazida, AgFeCHT na detecção de 4-clorofenol e Cd-PAMAM G.0-Ag/Fe na detecção de dopamina. A partir dos resultados obtidos, os materiais estudados se apresentaram bastante promissores para a detecção desses analitos, podendo ser incluídos no rol dos materiais com enorme potencialidade para a construção de sensores eletroquímicos para a detecção de isoniazida, dopamina e do 4-clorofenol.
The present work describes the chemical modification resulting from the interaction of β-cyclodextrin with PAMAM dendrimers G.0 and G.3 and chitosan, with electroactive bimetallic complexes. After the preparation and spectroscopic characterization of the studied bimetallic materials (Cd-PAMAM G.0-Ag/Fe, Cd-PAMAM G.0-Cu/Fe, Cd-PAMAM G.3-Cu/Fe, CuFeCHT and AgFeCHT ), a systematic study on the voltametric behavior of these materials, using electrochemical techniques, such as: cyclic voltammetry (VC) and squarewave voltammetry (SWV), using graphite paste electrodes was carried out. In addition, these bimetallic materials were tested for the detection of some analytes of biological and environmental interest such as: isoniazid, dopamine and 4-chlorophenol. Graphite paste electrodes containing Cd-PAMAM-type materials were sensitive to concentrations of dopamine, isoniazid and 4-chlorophenol and chitosan-based materials (CHT) were sensitive to isoniazid and 4-chlorophenol concentrations. After the catalytic electrooxidation tests of these substances, an investigation was carried out on the influence of the main interferents in the detection method, and the observed interference was not considered analytically significant. The recovery test of these substances from synthetic urine samples was also evaluated. Analyzing and comparing the best detection limit values, amperometric sensitivity and recovery efficiency in real samples, the materials that were highlighted: Cd-PAMAM G.0-Cu/Fe in the detection of isoniazid, AgFeCHT in the detection of 4-chlorophenol and Cd-PAMAM G.0-A /Fe in the detection of dopamine. From the obtained results, the materials studied were very promising for the detection of these analytes, and can be included in the list of materials with enormous potential for the construction of electrochemical sensors for the detection of isoniazid, dopamine and 4- chlorophenol.
The present work describes the chemical modification resulting from the interaction of β-cyclodextrin with PAMAM dendrimers G.0 and G.3 and chitosan, with electroactive bimetallic complexes. After the preparation and spectroscopic characterization of the studied bimetallic materials (Cd-PAMAM G.0-Ag/Fe, Cd-PAMAM G.0-Cu/Fe, Cd-PAMAM G.3-Cu/Fe, CuFeCHT and AgFeCHT ), a systematic study on the voltametric behavior of these materials, using electrochemical techniques, such as: cyclic voltammetry (VC) and squarewave voltammetry (SWV), using graphite paste electrodes was carried out. In addition, these bimetallic materials were tested for the detection of some analytes of biological and environmental interest such as: isoniazid, dopamine and 4-chlorophenol. Graphite paste electrodes containing Cd-PAMAM-type materials were sensitive to concentrations of dopamine, isoniazid and 4-chlorophenol and chitosan-based materials (CHT) were sensitive to isoniazid and 4-chlorophenol concentrations. After the catalytic electrooxidation tests of these substances, an investigation was carried out on the influence of the main interferents in the detection method, and the observed interference was not considered analytically significant. The recovery test of these substances from synthetic urine samples was also evaluated. Analyzing and comparing the best detection limit values, amperometric sensitivity and recovery efficiency in real samples, the materials that were highlighted: Cd-PAMAM G.0-Cu/Fe in the detection of isoniazid, AgFeCHT in the detection of 4-chlorophenol and Cd-PAMAM G.0-A /Fe in the detection of dopamine. From the obtained results, the materials studied were very promising for the detection of these analytes, and can be included in the list of materials with enormous potential for the construction of electrochemical sensors for the detection of isoniazid, dopamine and 4- chlorophenol.
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Palavras-chave
Ciclodextrina, Dendrímero PAMAM, Quitosana, Complexos metálicos, Voltametria Cíclica, Voltametria de Onda Quadrada, Eletrooxidação catalítica, Cyclodextrin, PAMAM dendrimer, Chitosan, Bimetallic complexes, Cyclic voltammetry, Square Wave Voltammetry, Catalytic electrooxidation