Flower-Doped Carbon Quantum Dots Improve Ceratobasidium sp. Growth Efficiency: A Green Nanotechnology Strategy for...

This study investigates the characteristics of AL (Anacamptis laxiflora flower)-doped carbon quantum dots (AL-CQDs), synthesised via a 7-h pyrolysis process and their effects on the growth of the Ceratobasidium sp. (AL5) fungus. AL-CQDs exhibited strong ultraviolet-visible absorption and a consistent spherical morphology. High-resolution transmission electron microscopy (HR-TEM) analysis revealed that the particles were homogeneously distributed, predominantly spherical or quasi-spherical in shape and ranged in size from 45 to 110 nm. In addition, the HR-TEM images showed localised ordered domains with an average interplanar spacing of approximately 0.113 nm, indicating the presence of graphitic or crystalline-like regions within the carbon dots. Fungal growth experiments demonstrated that nutrient media supplemented with CQDs significantly increased the growth rate and decreased hyphal diameter, suggesting more efficient nutrient uptake. The medium containing 2 g of CQDs promoted the fastest growth, reaching maximum levels by Day 5, whereas the 1 g CQD medium resulted in a more compact cell structure and steady growth. These findings suggest that AL-CQDs enhance fungal growth and may have promising applications in fungal biotechnology and nanobiotechnology.