Mitochondrion is one of the most important organelles in cells with several vital responsibilities. The consequence of a deficiency in the function of mitochondrion could result with the wide range of diseases and disorders. In this Study, we investigated the feasibility of utilizing surface-enhanced Raman scattering (SERS) to understand the mode of interaction of gold nanoparticles (GNPs) with mitochondria. The living lung cancer cells and the isolated mitochondria from these cells were treated with gold colloidal suspension for SERS experiments. The AFM images of the mitochondria confirmed that the treatment did not cause substantial damage to mitochondria. The localization of GNPs in living cells is investigated with confocal microscopy and found that GNPs form aggregates in the cytosol away from the mitochondria. However, SERS spectra obtained from isolated mitochondria and living cells indicate that GNPs escaped from the endosomes or entered into the living cell through another route may be in contact with mitochondria in a living cell. The findings of this study indicate that SERS can be used for mitochondrial research. (C) 2009 Elsevier B.V. All rights reserved.