Multifunctional Starch‐Based Sensor with Non‐Covalent Network to Achieve “3R” Circulation

Abstract With the consumption of disposable electronic devices increasing, it is meaningful but also a big challenge to develop reusable and sustainable materials to replace traditional single‐use sensors. Herein, a clever strategy for constructing a multifunctional sensor with 3R circulation (renewable, reusable, pollution‐reducing biodegradable) is presented, in which silver nanoparticles (AgNPs) with multiple interactions are introduced into a reversible non‐covalent cross‐linking network composed of biocompatible and degradable carboxymethyl starch (CMS) and polyvinyl alcohol (PVA) to simultaneously obtain high mechanical conductivity and long‐term antibacterial properties by a one‐pot method. Surprisingly, the assembled sensor shows high sensitivity (gauge factor up to 4.02), high conductivity (0.1753 S m −1 ), low detection limit (0.5%), long‐term antibacterial ability (more than 7 days), and stable sensing performance. Thus, the CMS/PVA/AgNPs sensor can not only accurately monitor a series of human behavior, but also identify handwriting recognition from different people. More importantly, the abandoned starch‐based sensor can form a 3R circulation. Especially, the fully renewable film still shows excellent mechanical performance, achieving reusable without sacrificing its original function. Therefore, this work provides a new horizon for multifunctional starch‐based materials as sustainable substrates for replacing traditional single‐use sensors.