Herein, we propose a high-performing thermoresponsive polyethylene glycol-coated tungsten-doped vanadium dioxide (W-VO2@PEG) nanoprobe (NP) with strong and switchable optical absorption in the near-infrared-II (NIR-II) biowindow (1000-1700 nm) near human-body temperature, to achieve deep and contrast-enhanced PA imaging.  Furthermore, in vivo potential of the prepared thermoresponsive NPs for the detection and identification of deep-seated tumors by directly comparing to conventional "always on" NPs has been demonstrated. 
THERM