We report the fabrication and application of ultra-short pulse laser induced nanostructures (NSs) on copper surface accomplished with different pulse energies and number of pulses. The shapes and sizes of NSs have been evaluated from the field emission scanning electron microscopy (FESEM) data which illustrated different ablation mechanisms in picosecond (ps) and femtosecond (fs) domains. The Cu NSs generated with ps pulses demonstrated Raman enhancements upto ~10 5 -10 8 in the case of the explosive molecules of 1,1-diamino-2,2-dinitroethene (FOX-7), 5 Amino, 3-nitro,1,3,5-nitrozole (ANTA) and 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20). The SERS studies were repeated two more times on the same substrate following a simple cleaning procedure.  We achieved considerable enhancement factors (of >10 5 ) for the Raman modes of an explosive molecule of FOX-7 on fs laser fabricated Cu NSs.