Facilitating astaxanthin precursor accumulation in Limnospira platensis through nitrogen‐doped carbon dots synthesized from bovine serum albumin

Abstract BACKGROUND Astaxanthin is widely recognized as one of the most potent natural antioxidants. However, the large‐scale production of astaxanthin remains a significant challenge due to the limitations of current chemical and biosynthetic methods. To address these challenges, this study explores the use of nitrogen‐doped carbon dots (N‐CDs) to enhance the accumulation of astaxanthin precursors (such as β‐carotene and zeaxanthin) in Limnospira platensis . RESULTS The N‐CDs exhibited excellent dispersibility, strong blue photoluminescence, and no detectable cytotoxicity. By optimizing cultivation parameters such as N‐CDs concentration (10 mg L −1 ), temperature (26 °C), light intensity (4500 lx), and nitrogen‐limited medium (NaNO 3 1.25 g L −1 ), effective improvements in biomass yield and bioactive compound accumulation were achieved. Under these optimized conditions, the biomass yield (1.48 ± 0.06 g L −1 ), β‐carotene accumulation (1.20 ± 0.01 g kg −1 ), and zeaxanthin accumulation (0.43 ± 0.02 g kg −1 ) increased by 140.32%, 96.72%, and 95.45%, respectively, compared to the control. CONCLUSION These findings demonstrate that N‐CDs can serve as a cost‐effective strategy for enhancing bioactive compound production in Limnospira platensis , offering a novel and efficient approach for biotechnological applications related to natural antioxidant production. © 2026 Society of Chemical Industry.