Rapid Detection of Escherichia Coli Using Graphene Oxide Based Electrochemical Sensor Chip

Detection of E. coli bacteria is imperative when it comes to potable water cleanliness and human health. E. coli when present in drinking water can cause ill health and its presence in urine is an indication of Urinary Tract Infection (UTI). This paper reports the development of rapid, easy to use, and low cost electrochemical sensor for detection of E.coli. The sensor is fabricated by drop casting graphene oxide (GO) on the screen printed carbon electrodes. Different bacteria dilutions were mixed with a fixed concentration of H2O2. Graphene oxide sheets allow for the indirect detection of bacteria by reducing the remaining concentration of H2O2 following the bacterial catalytic activity. This work presents GO synthesis, characterization, sample preparation and bacterial testing using H2O2 degradation. The sensor provides a response within a range of 0 to $2.7 \times 10^{3}$ CFU/mL and has a detection limit of 6.3 CFU/mL. The amount of time required for both response and recovery of the sensor is measured in milliseconds.