Fluorescence sensor for rapid identification of naproxen enantiomers using carbon quantum dot cyclodextrin complex and its application in the field of biological imaging

• This paper introduces a simple, rapid, and environmentally friendly method for the identification of naproxen chiral isomers. • The approach enables highly selective recognition and quantitative analysis of naproxen enantiomers through photoinduced electron transfer. • The rapid identification and separation of naproxen chiral isomers can be achieved in various aqueous environments. • Efficient recognition of naproxen chiral isomers was successfully demonstrated in both HeLa cells and zebrafish models. A novel fluorescent nanoprobe based on β-cyclodextrin-functionalized carbon quantum dots (β-CD-CQDs) was developed for the rapid recognition and enantioselective quantification of naproxen (NAP) enantiomers in aqueous environments. Leveraging the unique blue fluorescence of β-CD-CQDs and the host-guest inclusion capability of β-CD, a photoinduced electron transfer (PET) mechanism was established using methylene blue (MB) as an electron acceptor. Upon competitive displacement of MB by NAP enantiomers, differential fluorescence recovery was observed, with the (S)-enantiomer exhibiting approximately twofold higher restoration efficiency than the (R)-form, enabling clear chiral discrimination. The sensor demonstrated a broad linear detection range (0.5–380 μM) and low limits of detection (0.10 μM for S-NAP; 0.18 μM for R-NAP), with excellent selectivity and anti-interference performance in complex matrices. Furthermore, the β-CD-CQDs nanoprobe was successfully applied to confocal fluorescence imaging in HeLa cells and zebrafish embryos/larvae, achieving in situ enantioselective detection of NAP enantiomers in living systems. This work presents a simple, eco-friendly, and sensitive platform for the on-site monitoring and risk assessment of chiral pollutants in environmental waters and biological systems.