One-pot facile synthesis of CuNCs/RGO nanocomposite for the sensitive detection of heparin in human serum samples

A simple and facile one-pot approach for the synthesis of copper nanoclusters decorated reduced graphene oxide (CuNCs/RGO) nanocomposite was proposed, in which the CuNCs attached to the surface of the reduced glutathione (GSH) functionalized RGO through ligand exchange via their thiol functionalities. The synthesized nanocomposite was verified by structural characterizations, and the further investigation of density functional theory (DFT) indicated that Cu 3 R 2 cluster (R = C 10 H 16 O 6 N 3 S) with the lowest energy was the most stable structure in GSH-capped CuNCs. Although the CuNCs/RGO nanocomposite exhibited rather weak fluorescence, with the addition of heparin (Hep), the significant enhancement of fluorescence at 595 nm was achieved, which was developed to detect Hep in human serum samples with high selectivity and sensitivity. The mechanisms of fluorescence quenching of CuNCs/RGO nanocomposite and the sensing of Hep were discussed. The linear range was 0.1–10 μM with the detection limit of 26 nM in buffer solution containing 2% human serum sample, and satisfactory recovery in the range of 96.6%–104% was obtained, suggesting that the proposed method could applied to the detection of Hep in human serum samples.