Coplanar Capacitive Sensor Film from Nata de Coco-Reduced Graphene Oxide- Gelatin for Eco-Friendly Intelligent Food Packaging

Abstract The escalating global challenges of food waste and environmental pollution from conventional plastic packaging necessitate the development of sustainable and intelligent food packaging solutions. This study presents a novel bio-composite material fabricated from Nata de Coco (NDC), reduced Graphene Oxide (rGO), and food-grade gelatin, designed for smart and sustainable packaging applications. Material characterization confirmed the successful integration of rGO into the NDC-gelatin matrix, as evidenced by XRD and Raman spectroscopy. The composite exhibited suitable mechanical properties for packaging film applications. Electrical characterization using an LCR circuit demonstrated the material's promising sensing capabilities: capacitance measurements revealed frequency-dependent behavior, and the consistent downward shift in resonant frequency with increasing composite layers indicated its potential as a sensitive element. Crucially, the composite's ability to detect chemical changes relevant to food spoilage was validated through distinct shifts in resonant frequency upon interaction with varying concentrations of food-grade vinegar. This bio-based and intelligent composite offers a promising platform to address critical environmental and food safety challenges, paving the way for next-generation smart and sustainable food packaging.