How to eliminate ground noise for differential amplifier using op-amps, please suggest me some techniques.

 

You can try star grounding...all grounded points go to 1 ground bus on the board, then that buss is the only connection to the battery "-"....also, maybe bypassing your supply at the board with a 10uF cap, then a cap across the V- and V+ of about .1uF. Some noise is going to be present no matter what due to the movement of electrons...some opamps are quieter than others (ie., TL072 vs. LM741).