the invention described relates to the synthesis of gold nanorods in high concentrations in a single batch and their use in detection of nitroexplosives using surface enhanced raman spectroscopy . the nanoparticle suspensions were stable up to a month after preparation . the aggregated nanorods have a strong sers effect for nitroexplosives with sensitivity of 5 . 0 pg in a few seconds . the results obtained in numerous tests demonstrated a high reproducibility that makes aggregated nanorods very attractive substrates for defense and security applications .