Fig. 1. Characterization of AuSTs. Transmission electron micrographs of gold nanostars with Ag⁺ concentrations of (a) 1 mM, (b) 2 mM and (c) 4 mM. (d) XRD patterns of AuSTs. (e) Particle size of AuSTs. (f) Absorption spectra of AuSTs

Fig. 2. Photothermal property of AuSTs. (a) Temperature-time curves of AuSTs at different power densities. Under 808 nm, 2 W/cm² laser irradiation. (b) Time-temperature curve of AuSTs prepared with different Ag⁺ concentrations. (c) Temperature-time curves of AuSTs at different concentrations. (d) Temperature-time curves of AuSTs, AuNPs and DI Water. (e) Photothermal stability of AuSTs. (f) Graph of cooling period of the time versus negative natural logarithm of the temperature

Fig. 3. Biocompatibility test of AuSTs

Fig. 4. The photothermal therapy effect of AuSTs

Fig. 5. OCT imaging with AuSTs as contrast agents. OCT image of simulated tissue with (a) DI water, (b) PEG-200, and (c) AuSTs. (d) OCT signal intensity on depth of simulated tissue with DI water, PEG-200 and AuSTs. The OCT imaging effects of AuSTs in the eyes of crucian carp before (e) and after (f) injection. (g) Statistics on the signal strength of the area selected in (e) and (f)