Sustainable and Renewable Nano-biocomposites for Sensors and Actuators: A Review on Preparation and Performance

Background: Nanomaterials derived from sustainable and biodegradable polymers are currently the most attractive materials. Polymeric nano-biocomposites (PNBCs) are a specific class of materials derived by combining nanosized fillers with polymer materials, and the most commonly used nano-fillers are hydroxyapatite, organic or inorganic metal nanoparticles, clays, etc. Methods: Many recent research works have focused on utilizing biopolymer-based hydrogel materials for the fabrication of analyte sensors and electrode modifiers due to their high permeability and faster mobilization of electrons. Such biopolymer hydrogels utilize newer printing methods in electrode prototyping, which renders portable, flexible, and advanced bioelectronics sensors with high-performance characteristics. Few researchers have also stated the use of polyaniline reinforced biocomposites for fabricating electrochemical sensors and actuators because of their unique properties, making them a potential material choice for electronics applications. Results: Nanoparticles of polyaniline improve the detection limit and sensitivity of the sensor even when used for recognizing a single molecule. Bionanocomposites possess excellent thermo-mechanical properties in the designed nanocomposite, even at low nanoparticle concentrations. These materials possess higher hardness and stability, giving rise to excellent mechanical characteristics. Furthermore, incorporating nanoparticles into a biopolymeric matrix can enhance its electrical conductivity, barrier properties, and consistency. Also, the powerful interaction between biopolymers and functional groups of nanoparticles increases the strength of bionanocomposites. Conclusion: Nano-biocomposites-based biosensors were found to possess high specificity, sensitivity, and a wider target spectrum. The current review discusses the use of sustainable and renewable biocomposites for the preparation of biosensors and actuators, their properties like sensitivity, the limit of detection, advantages over the synthetic material, and environmental hazards.