Sustainable microplastic detection using boron-doped carbon dots synthesized from chicken feathers

Abstract Global poultry farming annually generates millions of tons of chicken feathers that often end up in landfills or waterways. In this study, we turn this biomass into fluorescent carbon dots (CDs) via a one-pot sonochemical synthesis, followed by in situ boron doping. The emission of the CDs is blue-shifted to shorter wavelengths by boron doping at 0, 5, 10, and 15 (%wt), producing bright blue photoluminescence. The emission peaks are further modified by changing the excitation energy. The existence of B-O-H and B-N functional groups added by the boron dopant is confirmed by FTIR spectroscopy. The 280 nm absorbance peak is ascribed to C=C bonds, whereas the 330 nm band is associated with C=O bonds, both of which are features of CDs. Boron doping encourages carbon dots to bind to PVC microplastics. When these CDs come into contact with PVC floating in water, their blue illumination diminishes proportionally to the concentration of the plastic, resulting in a “turn-off” reaction. As a result, boron-doped CDs made from chicken feathers recycle feather waste while also serving as a simple, portable sensor for PVC microplastic pollution in water.