ABSTRACT
Noble metal nanoparticles are one of the most powerful tools in nanotechnology, and are used to tune novel, purpose-built plasmonic nanostructures capable for intracellular probing. To date, in vitro applications of surface-enhanced Raman scattering (SERS) nanoprobes have been mainly directed into functionalization of gold nanoparticles (AuNPs) with a diameter between 20–100 nm. The wide interest in AuNPs results from their properties such as high chemical stability, easy control of size during synthesis, and various functionalizations with nanoprobes possessing usually the thiol and amine groups, and the most important issue is the high biocompatibility of gold. Since AuNPs are usually prepared by using the reduction of chloroauric acid with citrate ions, the latter are adsorbed on the gold introducing negative surface charges. An exciting aspect in the application of AuNPs for biosensing is designing multifunctional SERS nanosensors, which probe cellular environment to deliver chemical information and understand specific alternations in cellular machinery, including abnormalities in function of cells.
