Au@SiO₂@CuInS₂-ZnS/Anti-AFP fluorescent probe improves HCC cell labeling

Clear tumor imaging is essential to the resection of hepatocellular carcinoma (HCC). This study aimed to create a novel biological probe to improve the HCC imaging.

Au nano-flower particles and CuInS₂-ZnS core-shell quantum dots were synthesized by hydrothermal method. Au was coated with porous SiO₂ and combined with anti-AFP antibody. HCC cell line HepG2 was used to evaluate the targeting efficacy of the probe, while flow cytometry and MTT assay were used to detect the cytotoxicity and bio-compatibility of the probe. Probes were subcutaneously injected to nude mice to explore light intensity and tissue penetration.

The fluorescence stability of the probe was maintained 100% for 24 h, and the brightness value was 4 times stronger than that of the corresponding CuInS₂-ZnS quantum dot. In the targeting experiment, the labeled HepG2 emitted yellow fluorescence. In the cytotoxicity experiments, MTT and flow cytometry results showed that the bio-compatibility of the probe was fine, the inhibition rate of HepG2 cell with 60% Cu-QDs/Anti-AFP probe and Au-QDs/Anti-AFP probe solution for 48 h were significantly different (86.3%±7.0% vs. 4.9%±1.3%, t = 19.745, P<0.05), and the apoptosis rates were 83.3%±5.1% vs. 4.4%±0.8% (P<0.001). In the animal experiment, the luminescence of the novel probe can penetrate the abdominal tissues of a mouse, stronger than that of CuInS₂-ZnS quantum dot.

The Au@SiO₂@CuInS₂-ZnS/Anti-AFP probe can targetedly recognize and label HepG2 cells with good bio-compatibility and no toxicity, and the strong tissue penetrability of luminescence may be helpful to surgeons.