In precision agriculture and environmental monitoring, rapid and label-free sensing technologies are essential. Moreover, the widespread deployment of sensor networks in these fields requires sustainable solutions for both device fabrication and end-of-life disposal. Cellulose-based Raman sensors offer a promising approach to address these challenges. In this work, we present a biodegradable Raman sensing platform based on ethyl cellulose substrates functionalized with silver-coated MgFe hydrotalcite nanoplatelets. Using this device, we demonstrate the detection of cypermethrin, a widely used synthetic pyrethroid insecticide in large-scale agricultural applications.