This disclosure provides methods to use nanoparticles as non-optical tags for detecting a change in mass. chemical sensing or bio-sensing events or reaction upon conjugation of nanoparticles onto a thermoresistor heat sensor. Particularly described is the use of metal nanoparticles in thermal sensors, thermal bio-sensors, and sensing pixel arrays for multiple analyte sensing. In addition, an asymmetric filter is disclosed that allows size separation of molecules from nanoparticles. The asymmetric filter is a porous membrane that is designed to have a small pore size in one size and a large pore size on the other side.