Improving nanoprobes using surface-enhanced Raman scattering from 30-nm hollow gold particles.

We report the development of nanoprobes that exploit the surface-enhanced Raman scattering (SERS) from nonaggregated, hollow, gold nanospheres (HGNSs). The homogeneity of the HGNSs leads to a nearly 10-fold improvement in signal consistency over standard silver SERS substrates, which translates into a significant increase in sensitivity and dynamic range for the model application of pH sensing. Moreover, the small size (30-nm diameter) of these SERS-active nanoparticles represents a major step in advancing sensing technology based on SERS, making this technology more amenable to intracellular sensing.