Sol-gel derived metal oxide nanostructures based biosensors have shown potential application in various fields including mainly environmental and biological screening/monitoring. Composite film of CeO2-SiO2 has been fabricated using sol-gel technique to prepare enzymatic and DNA biosensor for the detection of triglyceride and cypermethrin, respectively. Lipase (Lip) and double stranded calfthymus (dsCT) was immobilized via physiosorption for the biosensing of respected analyte. The electrical response studies of Lip/CeO2-SiO2/ITO carried out using CV reveals linearity from 50 to 400 mg/dL with high sensitivity (2.28 mA/mg/dL). Electrochemical response studies of dsCT-DNA/CeO2–SiO2/ITO bioelectrode carried out as CM concentration using DPV technique exhibit detection limit up to 0.0025 ppm with response time of 30 sec. The finding of this study suggests that sol-gel derived metal oxides nanostructures of desired optical and electrical properties can be used for biosensor development to detect biomarkers in physiological range.