Preparation of DNA biosensor application from fuel oil waste by functionalization and characterization of MWCNT

Abstract

The potential of using a multi-wall carbon nanotube (MWCNT) synthesized from a fuel oil waste of power plants has discovered for the first time for DNA biosensors application. The MWCNT surface morphologies were examined by field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). The thickness of the MWCNT was found 203nm and confirmed by FESEM. The electrochemical DNA biosensor was successfully developed using a MWCNT modified on SiO2 thin films. The capacitance measurements were performed to detect the sensitivity of DNA detection. The change in capacitance before and after immobilization of the DNA was measured in the frequency range of 1Hz to 1MHz. The results indicate that bare device exhibited the lowest capacitance value, which was 32.7μF. The capacitance value of the DNA immobilization increase to 52μF. The permittivity and conductivity also were examined to study the effect of the DNA immobilization toward the MWCNT modified surface. This present demonstrated that the MWCNT modified SiO2 a thin film was successfully fabricated for DNA biosensor detection. Keywords: Carbon nanotubes, Sensors, Thin films, Electrochemical DNA