Reactivity of a Silsesquioxane Organofunctionalized with 4-Amino-5-Phenyl-4H-[1,2,4]-Triazole-3-thiol: Complementary Characterization and an Application to Chronoamperometric Detection of L-Dopamine

This work describes the organofunctionalization and a complementary characterization and application of an octakis(3-chloropropyl)octasilsesquioxane ( 1 ) with 4-Amino-5-Phenyl- 4H -[1,2,4]-Triazole-3-Thiol ( 2 ). The functionalized silsesquioxane ( 3 ) was characterized by nuclear magnetic resonance, X-ray diffraction, transmission electron microscopy and thermogravimetric analysis. After functionalized, the silsesquioxane can interact with copper chloride and subsequently with potassium hexacyanoferrate (III) ( 4 ). The hybrid composite formed ( 4 ) was characterized by FT-IR and diffuse reflectance. The compound 4 included into a work graphite paste electrode (20% w/w) was examined for chronoamperometric determination of L-Dopamine. The modified graphite paste electrode with compound 4 showed a linear response from 2.5× 10 − 5 at 4.0× 10 − 4 mol L − 1 . The modified graphite paste electrode with 4 showed a detection limit of 2.08× 10 − 4 mol L − 1 with a relative standard deviation of ± 2% ( n = 3) and amperometric sensitivity of 0.136 A mol L − 1 .