Figure 1.

(A) Self-assembly chemistry for creating hydrophobic paper using gas-phase trichloro(3,3,3-trifluoropropyl)silane reagent. (B) Photographs of whole blood samples prepared using the conventional dried blood spot microsampling method that collect samples through an absorption process for wet blood (Bi) and dried blood (Bii) spots on the hydrophilic paper. (C) Photographs showing whole blood deposited on hydrophobic paper substrate as (Ci) wet blood and (Cii) dried blood spheroids via an adsorption mechanism. We used 10 µL of whole blood for both microsampling methods on hydrophobic paper substrates treated for 30 min with trichloro(3,3,3-trifluoropropyl)silane.