A novel conductive biocomposite film (MWCNTsDNAcyt c) which contains multi-walled carbon nanotubes (MWCNTs) along with the incorporation of DNA and cytochrome c (cyt c) has been synthesized on glassy carbon electrode (GCE), gold (Au), indium tin oxide (ITO) and screen printed carbon electrode (SPCE) by potentiostatic methods. The presence of both MWCNTs and DNA in the biocomposite film enhances the surface coverage concentration ( ), increases the electron transfer rate constant (Ks) up to 21% and decreases the degradation of cyt c during the cyc領(lǐng). The biocomposite film also exhibits a promising enhanced electrocatalytic activity towards the reduction of halogen oxyanions and oxidation of biochemical compounds such as ascorbic acid and l-cysteine. The cyclic voltammetry has been used for the measurement of electroanalytical properties of analytes by means of biocomposite film modified GCEs. The sensitivity of MWCNTsDNAcyt c modified GCE possess higher values than the values obtained for DNAcyt c film modified GCE. Further, the reduction potentials of halogen oxyanions Epc, clearly shows that the activity of the biocomposite is dependent on the electronegativity of halogen oxyanions. Electrochemical quartz crystal microbalance studies revealed the enhancements in the functional properties of MWCNTs, DNA and cyt c.We have studied the surface morphology of the biocomposite films using scanning electron microscopy and atomic force microscopy, which revealed that DNA and cyt c have been incorporated on MWCNTs. Finally, the flow injection analysis has been used for the amperometric detection of analytes at MWCNTsDNAcyt c film modified SPCE. 掃描探針顯微鏡(SPM/AFM/STM)