We field-tested the sensor on three different surfaces of a biotechnology lab with a long history of using EtBr for electrophoresis related activity. The first sample is the surface of the fume hood, used specifically to prepare agarose gels with EtBr, thus it has a high risk of contamination being an area of intense activity in which the solution is used in its stock concentration. The second sample is the basin of exhausted gel, a surface which presents a moderate risk of contamination due to the leaks from the melting gel but mitigated by the UV exposure applied to the gels themselves. The last reading is an electrophoretic gel basin before use and therefore well cleaned a couple of days before. Due to the limit of the SEM we also check the structure changes in the working electrodes before and after the exposure to Ethidium bromide, the data collected suggested a slightly decrease in roughness and volume relatable to the electrical current activity rather than a corrosion operated by the Solution or due to a potential binding between the component of the Ethidium Bromide and the surface. (Fig. )