Voltammetric Behaviour of an Electroactive of Zn2+ - octa(aminopropyl)silsesquioxane nanocoposite : An Application to 4-Chlorophenol Detection in Tap Water

This paper presents the voltammetric behavior of electroactive metallosilsesquioxane and their use in the detection of 4-CP. The metallosilsesquioxane was synthesized in two steps. First by direct reaction between hydrochloride octa(aminopropyl)silsesquioxane (POSS-NH3+Cl-) and Zn2+ a second by electrostatic interaction with [FeCN6](4-) (SZnFe). The nanostructured material showed a well-defined three redox couples with formal potential (E9') of approximately 0.33, 0.78 and 1.01 +/- 0.01V (vs Ag/AgCl). Voltammetric analysis showed that the formal potential (E-theta') strongly depends on concentration and electrolyte type, but the system remained unchanged with pH values between 2 and 8. The SZnH graphite paste electrode exhibits a sensitive and catalytic oxidation response for the detection of 4-CP. For detection of 4-CP, the modified graphite paste electrode had a linear range of 6.0x 10(-7) to 6.0x 10(-5) mol L-1 with a limit of detection of 5.3 x10(-6) mol L-1 and a sensitivity of 0.53 A/mol L-1. This electrode could be used to detect 4-CP in tap water.