FOLH1 and prostate cancer: We previously investigated the shape effect of gold nanoparticles, and found that GNSs offer a superior SERS substrate with extremely high sensitivity.16 GNSs present self-generated “hot-spots” that result in substantive signal enhancement without the need to aggregate nanoparticles.17–19 Second, we hypothesized that PSMA, a type II integral membrane protein that is significantly over-expressed on the cell surface of most prostate cancers but particularly in castration-resistant, advanced and metastatic disease,20,21 could serve as a relevant target for SERS based imaging.