Cellulose nanofiber-polyaniline nanofiber-carbon dot nanohybrid and its nanocomposite with sorbitol based hyperbranched epoxy: Physical, thermal, biological and sensing properties

The increase of blood sugar level in the human body causes severe health issues. Several electrochemical and optical sensing methods were developed in this regard. However, the use of low cost, efficient chemosensors are mostly preferred for practical applications. In this context, a fluorescent nanohybrid of cellulose nanofiber (CNF) modified carbon dot (CD)-polyaniline nanofiber using a facile in-situ polymerization method was reported herein. The nanohybrid exhibited good sensing ability of glucose with concentration as low as 8 μM in 0.1 M phosphate buffer solution. Further, this nanohybrid was incorporated in different weight percentages in the bio-based hyperbranched epoxy consisting of sorbitol and monoglyceride of castor oil as bio-based components, in addition to the conventional reactants. The formation of the nanocomposites was verified using spectroscopic, microscopic and diffraction techniques. The thermosetting nanocomposites showed good mechanical properties, such as tensile strength (39 MPa), elongation at break (82%), scratch resistance (>10 kg) and impact resistance (16.5 kJ/m) and good thermal stability. The nanocomposites displayed good hematocompatibility with mammalian blood in accordance with anti-hemolytic studies. The nanocomposites exhibited better biodegradability compared to the pristine epoxy due to the presence of CNF and CD which accelerated the degradation process.