Perpetual Eze-Idehen

4.1. Sensor Performance Before measurement, the sensors were exposed to water-contaminated soil (4 mL) in a 70 °C water bath to assess hydrophobic properties. While a slight drift in the CB-PMMA sensor response was observed after 40 s, sensitivity remained unchanged between dry and wet contaminated soil (a,b). Similarly, baseline measurements in ambient air showed minimal resistance variation (a–d).