After completing the 16 mW Raman map scan, the same scan area was rescanned (Figure ) with 2 mW laser power to check the Eg peak shift after heating. A 2 mW low power was chosen as no morphological changes were observed, so there would be little change in peak shift due to plasmonic heating. The Raman spectra for the same spots (marked in black in Figure ) show rutile Eg mode peak shifts at 444, 442, 439, 442, and 443 cm -1 . To correspond the Eg peak shifts to temperature changes, a temperature versus Raman shift plot (Figure ) was calibrated (black dot) by annealing a bulk rutile crystal in a Linkam cell (Figure ). This calibration curve matches the calibration reported by Lan et al. During plasmonic heating with 16 mW laser (red marker), the temperature was recorded between 450°C and 650°C, whereas after it had been cooled down, the temperature (blue marker) ranged from 50°C to 150°C. A mean 450°C temperature difference is seen during and after the scan. The temperature was also calibrated using the stokes and antistokes Raman, as seen in Figure . The obtained temperature range during laser scanning is comparable to that obtained from the Raman peak shift. The measured temperature during laser scanning was lowered to 200 ~ 400 °C (Figure ) on the sample with low Au particle density (~75/μm 2 ). However, the measured temperature is too low to account for the phase transition and melting of the TiO2.