SERS provides great sensitivity at low concns. of analytes. SERS combined with near IR (NIR) resonant gold nanomaterials are important candidates for theranostic agents due to their combined extinction properties and sensing abilities stemming from the deep penetration of laser light in the NIR region. Here, highly branched gold nanoflowers (GNFs) grown from Pd and Pt seeds are prepd. and their SERS properties are studied. The growth was performed at 80 °C without stirring, and this high temp. growth method is assumed to provide great shape stability of sharp tips in GNFs. We found that seed size must be large enough (>30 nm in diam.) to induce the growth of those SERS-active and thermally stable GNFs. We also found that the addn. of silver nitrate (AgNO3) is important to induce sharp tip growth and shape stability. Incubation with Hela cells indicates that GNFs are taken up and reside in the cytoplasm. SERS was obsd. in those cells incubated with 1,10-phenanthroline (Phen)-loaded GNFs.