Sol–gel derived cerium-oxide–silicon-oxide nanocomposite for cypermethrin detection

Cerium oxide (CeO2) nanoparticles have been self-assembled onto sol–gel derived silicon-oxide (SiO2) film fabricated onto indium tin oxide (ITO) coated glass plate. These SiO2–CeO2 nanocomposite films have been used to immobilize the double stranded calf thymus deoxy ribose nucleic acid (dsCT-DNA) by physical adsorption to detect cypermethrin (CM). Both CeO2–SiO2/ITO electrode and dsCT-DNA/CeO2–SiO2/ITO bioelectrodes have been characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microsopy (SEM) and differential pulse voltammetry (DPV) to confirm the formation of CeO2–SiO2 nanocomposite and binding of dsCT-DNA with CeO2–SiO2 nanocomposite. Electrochemical response studies of dsCT-DNA/CeO2–SiO2/ITO bioelectrode carried out as a function of CM concentration using DPV technique exhibit detection limit up to 0.0025 ppm with response time of 30 s.