A Polyhedral Oligomeric Silsesquioxane (POSS) Doped with Cerium(III) / Fe(II) and its Application as an Electrochemical Sensor for L-dopamine

A Polyhedral oligomeric silsesquioxane (POSS) doped with cerium (III) was synthesized and reacted with potassium hexacyanoferrate (SCeH). The vibrational, structural, morphological and electrochemical properties of this compound were studied by Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopic, X-ray diffraction, Scanning electron microscopy, Energy dispersive X-ray and voltammetry using a modified graphite paste electrode. The modified paste electrode containing SCeH (SCeGPE) verified one redox pair with formal potential E θ’ = 0.33 V ± 0.01 ( vs Ag/AgCl, KCl, 1.0 mol L −1 ; v = 100 mV s −1 ), attributed to the Fe 2+ /Fe 3+ process in the presence of Cerium (III) cyanoferrate. The redox couple presents a high sensitivity and wide response range in the detection of L-dopamine. The limit of detection and amperometric sensibility were established at 4.08 × 10 –4 mol L −1 and 8.27 × 10 −6 mol L −1 employing the voltammetric and chronoamperometric methods respectively.