Using a laser intensity of 3 W cm -2 , the temperature of the black gold solution reaches a temperature of ~ 38°C.The pure water showed a negligible temperature change (~3.1K) under the same laser intensity. Additionally, the photothermal effect is modulated by changing the laser intensity, where the higher laser intensity tends to display a higher temperature increment. Indeed, the temperature increased to ~47 °C when the laser intensity was increased to 4 Wcm -2 .