Metallic nanoparticles: an interesting option for mass spectrometry imaging of small molecules in tissues

MALDI mass spectrometry imaging is a central technique for the visualisation and identification of a wide variety of molecules in biological samples, especially in tissues slides. However, organic matrices used for the desorption and ionisation of molecules suffers from major limitations, particularly for the analysis of small molecules due to interferences from the matrix in the low m/z range. In this preliminary study we compared the performances of 9-aminoacridine, a well known organic matrix used for small molecules anaylsis, and metallic nanoparticles to evaluate the information obtained from both method. Ionisation by nanoparticles is known as Surface-Assisted Laser Desorption Ionisation (SALDI). Metallic nanoparticles seem to be a promising substrate for MS analysis of small compounds in tissues and reveals information that are complementary to those obtained by MALDI.