Platinum- polydopamine @SiO2 nanocomposite modified electrode for the electrochemical determination of quercetin

Quercetin (QR) was electrochemically determined using a platinum-polydopamine coated silica particles modified glassy carbon electrode (Pt-PDA@SiO2/GCE). Pt-PDA@SiO2 was prepared by polymerization of dopamine on SiO2 particles followed by loading of Pt nanoparticle via sodium borohydride (NaBH4) reduction method. The surface morphology of the Pt-PDA@SiO2 nanoparticles, functional groups of PDA@SiO2 and crystalline nature of the nanoparticles were characterized by FE-SEM, FTIR and XRD, respectively, The Pt-PDA@SiO2/GCE modified electrode electro active surface area and conductivity of the modified electrodes were calculated using as Fe3+/Fe2+ probe. Quercetin was quantified by Pt-PDA@SiO2/GCE modified electrode square wave voltammetry (SWV). The Pt-PDA@SiO2/GCE exhibited good electrocatalytic activity towards the electrochemical oxidation of QR with excellent reproducibility and stability. The modified electrode shows an excellent detection limit and sensitivity of 16 nM (S/N = 3) and 6.47 μA/μM, respectively. The analytical utility of the Pt-PDA@SiO2/GCE was checked by determining the QR in various real samples such as tea, onion extract, apple juice, human urine and blood plasma.