Transition-Edge Sensors (TESs) are extremely sensitive microcalorimeters, which take advantage of the sharpness of the superconducting transition. Use of proximity Mo/Au bilayers allows tuning critical temperature Tc. Study of superconducting proximity effect reveals a high quality interface and tracks the evolution of Tc with layers thicknesses. Nevertheless, the transition is hugely broadened by current, which can be interpreted as current-driven vortex-antivortex depairing. Both effects have impact on performances of TES-based radiation detectors, in development at the ICMAB.