A Facile Synthesis of Ferrocene Functionalized Graphene Oxide Nanocomposite for Electrochemical Sensing of Lead

Ferrocene, an organometallic compound has the potential to undergo reversible oxidation even at low potential which makes it suitable for electrochemical sensor applications. The potential of graphene oxide has been widely exploited in electrochemistry, since they serve as an excellent platform for electrochemical molecules and increase the electrochemical properties. The potential of Graphene oxide-ferrocene (GO-Fc) nanocomposites has not been realized much in fabrication of electrochemical sensors. Hence, the electrochemical properties of the pure Ferrocene and GO-Fc nanocomposites were investigated. Graphene oxide (GO) was synthesised by modified Hummer's method and was conjugated with ferrocene at different weight ratio after thermal treatment. The as-prepared pure GO and GO-Fc nanocomposites were characterized by various analytical methods. Monoclinic phase of Ferrocene was observed in XRD. Surface functionalization of Ferrocene on GO was imaged by TEM. Ferrocene particles were observed to be rod shaped and functionalized on surface of GO in TEM images. The composite formation was validated by FTIR and Raman by the presence of aromatic ring and ferrocene bands respectively. AAS results showed 87% ferrocene loading capacity in GO-Fc composite 2 (GF2) which decreased to 77% in GO-Fc composite 5 (GF5). Based on the CV curves, and ferrocene loaded on GO, GO-Fc composite 4 (GF4) was chosen for evaluating the lead sensing property. The sensing studies showed a detection limit of 0.168 A mu g/l with significant sensitivity up to 250 A mu g/l. The results indicate that GO-Fc nanocomposites can be potentially used for sensing lead in environmental samples.