Accessing BCG in infected macrophages by antibody-mediated drug delivery system and tracking by surface-enhanced Raman scattering spectroscopy.

Gold nanoparticles (AuNP) modified with antibody and rifampicin (RP) were tested against Mycobacterium bovis Bacillus Calmette-Guérin (BCG), which previously generated in vitro infection of macrophages from mice. Such a drug delivery system works as nanocarrier for RP and presented lower toxicity for macrophages cells than each separated component. Surface-enhanced Raman scattering (SERS) spectroscopy and fluorescence microscopy were used as analytical tools for the characterization of the internalization of gold nanocarriers into macrophage cells.

Tracking chemical interactions of folic acid on gold surface by SERS spectroscopy.

Surface-enhanced Raman scattering (SERS) spectroscopy was used in the investigation of the adsorption of folic acid (FA) on the surface of gold nanoparticles (AuNPs) in the absence and presence of surface modifiers hydrochloride acid (HCl) and 1-mercaptoethanol (ME). The proposal for the chemical interactions of FA with the metallic surface was based on vibrational assignment supported by Density Functional Theory (DFT) calculations. In the absence of surface modifiers, FA interacts with the gold surface through the pteridine moiety in a tilted geometry.