Abstract: The present invention provides multifunctional popcorn-shaped gold nanomaterial for sensing, treatment and for a unique way of monitoring treatment effectiveness during therapy process of different human cancer cells and pathogenic bacteria. It consists of the following steps 1) Synthesis of popcorn-shaped gold nanoparticles of different sizes. 2) Design of multifunctional popcorn-shaped gold nanoparticle for targeted sensing, therapy and monitoring therapy effectiveness for different human cancer cells (liver, breast, skin and prostate) and drug resistance bacteria. 3) Design of portable SERS sensor for cancer detection, treatment and for monitoring treatment effectiveness using the same instrument. and 4) Application of our approach to detect and kill MDRB from food sample.