Abstract
This study demonstrates a one-step hydrothermal synthesis of bright yellow phosphorus-doped carbon quantum dots (P-CQDs) using Caesalpinia sappan L. as carbon source. Comprehensive characterization through TEM, XPS, UV-Vis and FTIRspectroscopy confirmed the successful formation of P-CQDs. The obtained P-CQDs exhibited exceptional selectivity and was capable of detecting ciprofloxacin across a wide linear range of 0.01–0.1 µM, with a LOD determined to be 2.06 nM. Antimicrobial assays revealed MIC values of 7.14 µg/mL and 8.33 µg/mL against S. aureus and E. coli, respectively. Practical application studies confirmed their efficacy for rapid CIP detection in milk samples, establishing a novel sensing platform for food safety monitoring. This work provides valuable insights into the multifunctional applications of carbon dots in food chemistry and biomedical fields.
Data availability
Data will be made available on request.
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Funding
This research was funded by Chongqing Three Gorges Medical College 2023 University-level Natural Science Project (Grant No. XJ2023000204), Chongqing Clinical Pharmacy Key Specialties Construction Project and Chongqing science and health joint medical research project (Grant No. 2022MSXM053).
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All authors contributed to the study conception and design. **Shuchen Pei** : Validation, Writing-review & editing. **Kangli Yan** : Formal analysis and Writing-original draft. **Shaoyu Cai** : Data curation. **Yinjun Hou** : Software. **Kang Luo** : Methodology. **Pu Xiang: ** Writing-review & editing. **Yang Peng** : Project administration.
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Pei, S., Yan, K., Cai, S. et al. Preparation of carbon quantum dot fluorescent probe from Caesalpinia sappan L. for the detection of ciprofloxacin and antibacterial applications. Sci Rep (2026). https://doi.org/10.1038/s41598-026-48145-7
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DOI: https://doi.org/10.1038/s41598-026-48145-7
