Selective Fabrication of an Electrochemical Sensor for Pb2+ Based on Poly(pyrrole-co-o-toluidine)/CoFe2O4 Nanocomposites

We report the synthesis of a novel nanocomposites based Poly(pyrrole-co-o-toluidine) copolymer and cobalt ferrite (CoFe2O4) as an electrochemical sensor for selective Pb(2+)detection. The general abbreviation of these new materials are given as P(Py-co-OT)/CF nanocomposites (P(Py-co-OT)/CF NCs). The synthesis was performed via in situ-chemical oxidative polymerization method at different CoFe2O4 weight ratio (5%, 10%, 30%, 50% and 70%), whereas CoFe2O4 nanoparticle (NPs) was synthesized by an egg white method prior the nanocomposite formation. The structural, morphological, thermal, magnetic, electrical and electrochemical properties of pure P(Py-co-OT), CoFe2O4 and P(Py-co-OT)/CF NCs were characterized by XRD, FTIR, TGA-DTG, SEM-EDX, TEM, VSM and electrical conductivity. The results of XRD and FTIR confirmed the formation of P(Py-co-OT)/CF NCs with the component CoFe2O4 showing spinel structure. The analysis of TGA-DTG presented that CoFe2O4 NPs improved the thermal stability of NCs indicated the presence of some interactions between the interface of P(Py-co-OT) and CoFe2O4 NPs, which affects the chemical and physical properties of the NCs. The ac conductivity was also examined as a function of temperature. The measures showed a decrease in the conductivity of NCs when increasing the insulating CoFe2O4 NPs contents. A cost-effective and reliable electrochemical sensor selective to Pb2+ ion was fabricated using P(Py-co-OT)/CF NCs on glassy carbon (GCE). It was found that the P(Py-co-OT)/CF10 NCs exhibit excellent detection of Pb2+ ion. The proposed Pb2+ ion sensor was performed linearly over the large concentration range of 0.1 nM similar to 0.01 mM labelled as linear dynamic range (LDR). The sensitivity as well as detection limit were estimated to be 22.39 mu A mu M(-1)cm(-2) and 42.39 +/- 2.12 pM, respectively. The desired ionic sensor-based on P(Py-co-OT)/CF10 NCs/binder/GCE was found as efficient to detect Pb2+ ion in environmental and biological samples significantly. The analytical sensor performances such as reproducibility, sensitivity, stability, validation, and response time were reliable and significant.