Fig. 2.

Photophysical properties of Au@SiNRs. a Photoluminescence spectra (λ_ex = 360 nm) and insert photographs of Au@SiNRs, SiNRs, and AuNPs from left to right. b UV–vis-NIR absorbance spectra of Au@SiNRs (300 μg mL⁻¹), SiNRs (300 μg mL⁻¹), and AuNPs (0.01 M). c Heating curves of Au@SiNRs solutions with different concentrations and SiNRs aqueous suspension (400 μg mL⁻¹) at 1.2 W cm⁻² for 600 s. d Infrared thermal images of Au@SiNRs suspensions (300 μg mL⁻¹) irradiated with 808 nm laser at a variety of power densities for 0–10 min. e Heating–cooling curves of Au@SiNRs (300 μg mL⁻¹), SiNRs (300 μg mL⁻¹), and AuNPs (0.01 M). f The five-cycle photothermal profiles of Au@SiNRs (300 μg mL⁻¹). g PA Imaging of Au@SiNRs with different concentrations