Two approaches for sample preparation using NP. (A) The dried-droplet approach that was applied in this study with evaporation of the solvent between steps 2 and 3. (B) A proposed approach for space missions, where NPs are first positioned on the sample holder substrate before applying the sample. The first deposition of the NPs might even be performed prelaunch. Solvent evaporation occurs between steps 2 and 3, as well as between steps 4 and 5. Additionally, after step 5, drop casting of the sample can be repeated to further increase the analyte amount, if needed.