Fabrication of E-coli bacteria Biosensor and Measurement under UV radiation

In the present article, a bio-sensor is fabricated to detect different concentrations of the E.coli bacteria existed in water by using zinc oxide nanorods. To make this biosensor, printed circuit board based electrodes are designed and made in an interdigitated shape. The hydrothermal method is used to grow the zinc oxide nanorods on the copper electrodes. By using this sensor, different concentrations of the E.coli bacteria in water are measured. When the sensor is adjacent to the bacteria, the resistance is changed because of the sensor reactions with the zinc oxide. The output is an amplified voltage which is increased as the result of the resistance change between the copper electrodes. Results are remeasured for the sensor in the presence of the UV light and then they are compared with the UV-free results. Experiments have shown that when the UV light is used, the voltage drop is more visible in the sensor output which represents the zinc oxide reactions in the presence of the UV light.