Comparing thermoplastic electrode materials: Toward enhanced sensing of O₂ and H₂O₂ in flow devices

Carbon composite electrodes often suffer from poor electrocatalytic activity and require complex, expensive, or time‐consuming modifications to effectively detect certain analytes such as O 2 and H 2 O 2 . Thermoplastic electrodes (TPEs) are a new class of composite electrodes, fabricated by mixing commercial graphite with a thermopolymer, that exhibit superior electrochemical properties to typical carbon composite electrodes. This work investigates the properties of TPEs using two thermopolymer binders – polycaprolactone (PCL) and polystyrene (PS) – with sanded and heat‐pressed surface treatments. XPS and SEM analysis suggested that sanded TPEs have a higher density of graphitic edge planes and improved electrochemistry as a result. Electrochemical detection of O 2 and H 2 O 2 was demonstrated on sanded PS TPEs. Additionally, this work introduces the first use of a 3D‐printed TPE template as part of a 3D‐printed sensor module that is reversibly sealed with magnets as a proof‐of‐concept flow‐based sensor for detecting H 2 O 2 .