Fig. 1. Characterization of AMNFs. (a) Transmission electron micrograph(TEM) of AMNFs; (b) TEM of AMNFs modified with sodium citrate; (c) atomic force micrograph of AMNFs in Fig.1(b); (d) size distribution of uniformly dispersed large-scale(50--55 mm) AMNFs in Fig.1(b)

Fig. 2. Optical properties of AMNFs. (a) Absorption spectra of AMNFs with different concentration; (b) photothermal conversion performance of AMNFs

Fig. 3. Photoacoustic performance of AMNFs. (a) TEM of AMNFs; (b) size distribution of AMNFs in Fig.3 (a); (c) photoacoustic signal of AMNFs at 808 nm; (d) photoacoustic signals of AMNFs and graphene oxide (GO) at 808 nm

Fig. 4. Photoacoustic imaging of tumor site at various time. (a) Photoacoustic imaging of tumor site at various time after 200 μL 3 mg/mL AMNFs injection; (b) photoacoustic signal of the tumor site at various time after 200 μL 3 mg/mL AMNFs injection

Fig. 5. Laser confocal microscopy imaging of MCF-7 cells cultivated 24 h with AMNFs in various concentrations