Fe₂O₃ Nanorod/Bacterial Cellulose Carbon Nanofiber Composites for Enhanced Acetone Sensing

Structures and performances from nature provide ideas for humans to deal with energy and environmental crisis. Inspired from natural structures, bacterial cellulose nanofibers with a fine-meshed network were selected as the raw materials to design acetone gas sensors. Here, Fe 2 O 3 nanorods were successfully introduced on the surface of carbon nanofibers by a feasible hydrothermal catalytic carbonization at 120 °C. Lots of heterojunctions between the bacterial cellulose carbon nanofiber and the Fe 2 O 3 nanorod were constructed, resulting in high gas-sensing properties to acetone vapor. At room temperature, the response of Fe 2 O 3 /bacterial cellulose carbon nanofiber composite (BCCF–Fe 2 O 3 ) to 5 ppm of acetone reached 2060% within 10 s. BCCF–Fe 2 O 3 showed high sensitivity and selectivity, ppb-level detection limit (100.7 ppb), nice long-term stability (30 days), low energy consumption (1.4 μW), and good anti-humidity performance in acetone detection. To our surprise, BCCF–Fe 2 O 3 had realized ultrasensitive exhaled acetone detection within 16 s, proving an effective and inexpensive strategy for diabetic noninvasive diagnosis.