Fig. 1: Experimental schematic.

The exploitation of fluctuations in the near-contact crossover regime at tip–surface separations zc = 2.5–3.5 nm with ultra-light tapping amplitude (A < 3 nm). Free amplitude A0 and setpoint amplitude Asp are judiciously optimized. The dynamic response of interaction with soft drug clusters leads to a two-stage distribution in phase giving an apparent phase contrast \(\phi ^ \ast\). DxO@mGO and MxD@mGO represent Doxorubicin and Minoxidil clusters on multilayered graphene oxide (mGO) respectively.