Edible oils as bio-plasticisers for sustainable additive manufacturing: comparative electrochemical performance and sensing of ascorbic acid in juices

We report the production of five separate high-performance conductive filament, using different edible oils (coconut oil, olive oil, a vegetable oil blend, sunflower oil, and rapeseed oil) as bio-plasticising compounds alongside recycled PLA and carbon black (CB) for additive manufacturing electrochemistry. Each filament was assessed through TGA, SEM, XPS, Raman and electrochemical scan rate studies, showing comparable electrochemical behaviour towards conventional redox probes, however, the materials containing coconut oil and olive oil exhibited distinct morphologies (as observed via SEM) and superior electroanalytical performance for the detection of ascorbic acid. These electrodes achieved detection limits of 2.45 and 2.14 μM, respectively. The electrode incorporating coconut oil was applied to the determination of ascorbic acid in real juice samples, yielding satisfactory recovery rates without the need for complex sample preparation. This study highlights the use edible, bio-based plasticisers in fabricating sustainable, high-performance filaments for sensing applications in food monitoring field.