Disclosed herein is an analytical aid comprising a surface that is at least partly coated with a hydrophilic coating, said hydrophilic coating containing nanoparticles with a silica structure and an average particle size ranging from 1 to 500 nm, determined according to DIN ISO 22412:2008. Additionally disclosed is a method for producing an analytical aid and sampling device containing the aforementioned analytical aid that is at least partly coated.
