Mesoporous silica xerogel modified with bridged ionic silsesquioxane used to immobilize copper tetrasulfonated phthalocyanine applied to electrochemical determination of dopamine

• Published in: Journal of solid state electrochemistry Vol. 19; no. 7; pp. 2095 - 2105
• Main Authors: Deon, Monique, Caldas, Elisangela Muncinelli, da Rosa, Danielle Santos, de Menezes, Eliana Weber, Dias, Silvio Luis Pereira, Pereira, Marcelo Barbalho, Costa, Tania Maria Haas, Arenas, Leliz Ticona, Benvenutti, Edilson Valmir
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2015
• Subjects: Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Electrochemistry; Energy Storage; Original Paper; Physical Chemistry; Hydroxytyramine; Charged organosilanes; Electrochemical dopamine determination; Silica-based hybrid material
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-014-2687-5

Silica xerogel was modified with an ionic silsesquioxane containing the cationic 1,4-diazoniabicyclo[2.2.2]octane bridged group and it was used as matrix for immobilization of copper tetrasulfonated phthalocyanine, resulting in Si/Db/CuTsPc material. This material was characterized by ultraviolet-visible and infrared spectroscopy, elemental and thermogravimetric analyses, nitrogen adsorption-desorption isotherms, and scanning electron microscopy. The Si/Db/CuTsPc material was used to develop a carbon paste electrode for dopamine determination. The electrochemical behavior of dopamine was evaluated by cyclic voltammetry and chronoamperometry. The optimal experimental conditions were determined (pH = 4.5 and oxygen atmosphere) using a 0.1 mol L −1 phosphate buffer solution. The carbon paste electrode modified with the Si/Db/CuTsPc material shows a linear response for current intensity with the dopamine concentration in the range of 0.010 to 0.107 mmol L −1 . The detection limit was 0.42 μmol L −1 , and the sensitivity was 7.15 μA (mmol L −1 ) −1 , making the system promising to be applied as electrochemical sensor for dopamine.