Fig. 6

 A In vitro PA images and corresponding signal intensities of Au@Cu_2-xSe aqueous dispersions with different concentrations. B In vivo PA images of tumor and C corresponding signal intensities obtained at different time points after intravenous injection of Au@Cu_2-xSe NPs (2 mg mL⁻¹ in saline, 200 µL). D In vitro CT images and corresponding HU values of Au@Cu_2-xSe aqueous dispersions with different concentrations. E In vivo CT images of tumor (indicated by white arrow) and F corresponding HU values obtained at different time points after intravenous injection of Au@Cu_2-xSe NPs (2 mg mL⁻¹ in saline, 200 µL). Data are presented as mean ± s.d. (n = 3)