Fig. 5

In vitro and in vivo PA imaging. a In vitro PA signal intensities at 1250 nm and corresponding PA images of AuNDs aqueous solution at different concentrations (0, 0.25, 1.0, 2.0, 4.0, 5.0 mg/mL). b, c In vivo PA signal intensities at 1250 nm and corresponding PA images combined with ultrasonic images of tumorous tissue at varied time points (0, 4, 8, 12, 24, 48 h) after intravenous injection of AuNDs aqueous solution