Mass spectrometry imaging of fingerprint sweat on nanostructured silicon†

Desorption ionisation on porous silicon mass spectrometry imaging (DIOS-MSI) was used on fingerprints to map the distribution of exogenous and endogenous molecules present in sweat. Our attention was focused on the proof-of-principle to detect illicit drugs and their metabolites to exemplify the technique's potential in the area of forensic and workplace testing.