Bacteria-specific biosensor development mediated via multi-walled carbon nanotube

As we are exposed to more bacteria and pathogens with the increasing pollution, research is increasing for their quick and easy detection. Nanotubes with high electron conductivity, which can bind different molecules to large surface areas, are widely used in the development of electrochemical biosensors. In this study, an electrochemical biosensor design is presented by integrating 5 % gold plated tungsten wires and acid-functionalized multi-walled carbon nanotubes in a two-step coating process. Gold-plated tungsten wires (0.05 mm) were coated with acid-functionalized short multi-walled carbon nanotubes. The TEM and SEM images taken confirmed that the tungsten wire was coated uniformly and homogeneously. The FTIR results show that the immobilization of the electrodes takes place efficiently. Escherichia coli K-12 detection performance was evaluated by changes in electrical currents after antikor-antigen interactions. Electrochemical Impedance Spectroscopy was used as the measurement system, which allows very sensitive results in biosensor systems. Signal measurements were taken at 50 Hertz, which is the most efficient since it is ohmic. Interaction signals were evaluated at approximately 1.0 V. The current value changed from Vpp = 168.40 mV to Vpp = 198.57 mV, indicating high detection ability for a 0.5 % (V/V) concentration of E. coli K-12 strain. Our data shows that the multi-walled carbon nanotube-based biosensor can be developed as a biosensor for Escherichia coli K-12 detection.