A portablemagnetic surface Raman-enhanced scattering (SERS) nanoparticle arrays platform would be developed for magnetic separationSERS detection of environmental, water,biomolecules samples. It is very simplerapid platform with portable Raman spectroscopy to detect samples (bacteria, virous, water toxicants) after magnetic separation processes, without labelling the fluorescence dye,the limit of detection concentration is lower than 10-8 M.